Wireless power reception device and wireless power transmission device

ABSTRACT

A wireless power reception device according to an embodiment of the present specification comprises a controller for: receiving wireless power from a wireless power transmission device, and performing power pickup for receiving the wireless power from the wireless power transmission device by magnetic coupling with the wireless power transmission device at an operating frequency; and communicating with the wireless power transmission device by using at least one of in-band communication using the operating frequency and out-band communication using a frequency other than the operating frequency, and controlling reception of the wireless power, wherein, in the power transmission step of receiving the wireless power, the controller transmits or receives, using the in-band communication, a message for controlling the wireless power, and transmits or receives, using the out-band communication, an authentication message for authentication of the wireless power transmission device.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present specification relates to a data exchange method usingout-band communication and in-band communication between a wirelesspower receiver and a wireless power transmitter.

Related Art

The wireless power transfer (or transmission) technology corresponds toa technology that may wirelessly transfer (or transmit) power between apower source and an electronic device. For example, by allowing thebattery of a wireless device, such as a smartphone or a tablet PC, andso on, to be recharged by simply loading the wireless device on awireless charging pad, the wireless power transfer technique may providemore outstanding mobility, convenience, and safety as compared to theconventional wired charging environment, which uses a wired chargingconnector. Apart from the wireless charging of wireless devices, thewireless power transfer technique is raising attention as a replacementfor the conventional wired power transfer environment in diverse fields,such as electric vehicles, Bluetooth earphones, 3D glasses, diversewearable devices, household (or home) electric appliances, furniture,underground facilities, buildings, medical equipment, robots, leisure,and so on.

The wireless power transfer (or transmission) method is also referred toas a contactless power transfer method, or a no point of contact powertransfer method, or a wireless charging method. A wireless powertransfer system may be configured of a wireless power transmittersupplying electric energy by using a wireless power transfer method, anda wireless power receiver receiving the electric energy being suppliedby the wireless power transmitter and supplying the receiving electricenergy to a receiver, such as a battery cell, and so on.

The wireless power transfer technique includes diverse methods, such asa method of transferring power by using magnetic coupling, a method oftransferring power by using radio frequency (RF), a method oftransferring power by using microwaves, and a method of transferringpower by using ultrasound (or ultrasonic waves). The method that isbased on magnetic coupling is categorized as a magnetic induction methodand a magnetic resonance method. The magnetic induction methodcorresponds to a method transmitting power by using electric currentsthat are induced to the coil of the receiver by a magnetic field, whichis generated from a coil battery cell of the transmitter, in accordancewith an electromagnetic coupling between a transmitting coil and areceiving coil. The magnetic resonance method is similar to the magneticinduction method in that is uses a magnetic field. However, the magneticresonance method is different from the magnetic induction method in thatenergy is transmitted due to a concentration of magnetic fields on botha transmitting end and a receiving end, which is caused by the generatedresonance.

SUMMARY OF THE DISCLOSURE

An object of the present specification is to provide a wireless powertransmitter and a wireless power receiver that perform an authenticationprotocol using out-band communication.

The technical problems of the present specification are not limited tothe problems mentioned above, and other problems not mentioned will beclearly understood by those skilled in the art from the followingdescription.

A wireless power receiver, which receives a wireless power from awireless power transmitter, according to an embodiment of the presentspecification for solving the above problems comprises a power pickupconfigured to receive the wireless power from the wireless powertransmitter by magnetic coupling with the wireless power transmitter atan operating frequency and a controller configured to communicate withthe wireless power transmitter using at least one of in-bandcommunication using the operating frequency and out-band communicationusing a frequency other than the operating frequency and to control thereception of the wireless power, wherein, in a power transfer phase forreceiving the wireless power, the controller is configured to transmitor receive a message for controlling the wireless power using thein-band communication, and transmit or receive an authentication messagefor authenticating the wireless power transmitter using the out-bandcommunication.

A wireless power transmitter, which transfer a wireless power to awireless power receiver, according to an embodiment of the presentspecification for solving the above problems comprises a power converterconfigured to transfer the wireless power to the wireless power receiverby magnetic coupling with the wireless power receiver at an operatingfrequency and a controller configured to communicate with the wirelesspower receiver using at least one of in-band communication using theoperating frequency and out-band communication using a frequency otherthan the operating frequency and to control the transfer of the wirelesspower, wherein, in a power transfer phase for transferring the wirelesspower, the controller is configured to transmit or receive a message forcontrolling the wireless power using the in-band communication, andtransmit or receive an authentication message for authenticating thewireless power transmitter using the out-band communication.

Other specific details of this specification are included in thedetailed description and drawings.

Since the authentication message according to the authenticationprotocol is exchanged through out-band communication, which has a fastercommunication speed than in-band communication, the authenticationprotocol can be rapidly progressed and completed.

Even while the authentication message is transmitted/received throughout-band communication, messages for wireless power control aretransmitted/received through in-band communication, a message forwireless power control can be stably transmitted/received regardless ofthe progress of the authentication protocol.

Even if the power transmission stage is entered, wireless powertransmission/reception is performed in the low power mode untilauthentication of the wireless power transmitter and/or the wirelesspower receiver succeeds, it is possible to protect the wireless powerreceiver or the wireless power transmitter from the uncertified wirelesspower transmitter or the uncertified wireless power receiver.

The effect according to the present document is not limited by thecontents exemplified above, and more various effects are included in thepresent specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a wireless power system (10) according toan exemplary embodiment of the present disclosure.

FIG. 2 is a block diagram of a wireless power system (10) according toanother exemplary embodiment of the present disclosure.

FIG. 3 a shows an exemplary embodiment of diverse electronic devicesadopting a wireless power transfer system.

FIG. 3 b shows an example of a WPC NDEF in a wireless power transfersystem.

FIG. 4 a is a block diagram of a wireless power transfer systemaccording to another exemplary embodiment of the present disclosure.

FIG. 4 b is a diagram illustrating an example of a Bluetoothcommunication architecture to which an embodiment according to thepresent disclosure may be applied.

FIG. 4 c is a block diagram illustrating a wireless power transfersystem using BLE communication according to an example.

FIG. 4 d is a block diagram illustrating a wireless power transfersystem using BLE communication according to another example.

FIG. 5 is a state transition diagram for describing a wireless powertransfer procedure.

FIG. 6 shows a power control method according to an exemplary embodimentof the present disclosure.

FIG. 7 is a block diagram of a wireless power transmitter according toanother exemplary embodiment of the present disclosure.

FIG. 8 shows a wireless power receiver according to another exemplaryembodiment of the present disclosure.

FIG. 9 shows a communication frame structure according to an embodiment.This may be a communication frame structure in a shared mode.

FIG. 10 is a structure of a sync pattern according to an exemplaryembodiment.

FIG. 11 illustrates operation states of a wireless power transmitter anda wireless power receiver in a shared mode according to an embodiment.

FIG. 12 is a diagram illustrating a message field of a configurationpacket (CFG) of a wireless power receiver according to an embodiment.

FIG. 13 is a diagram illustrating a message field of a capability packet(CAP) of a wireless power transmitter according to an embodiment.

FIG. 14 is a diagram for explaining an out-band communication connectionprocedure and an authentication procedure according to an embodiment.

FIG. 15 is a diagram for explaining an out-band communication connectionprocedure and an authentication procedure according to anotherembodiment.

FIG. 16 is a diagram schematically illustrating a wireless powertransmission procedure according to an embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

In this specification, “A or B” may refer to “only A”, “only B” or “bothA and B”. In other words, “A or B” in this specification may beinterpreted as “A and/or B”. For example, in this specification, “A, B,or C” may refer to “only A”, “only B”, “only C”, or any combination of“A, B and C”.

The slash (/) or comma used in this specification may refer to “and/or”.For example, “A/B” may refer to “A and/or B”. Accordingly, “A/B” mayrefer to “only A”, “only B”, or “both A and B”. For example, “A, B, C”may refer to “A, B, or C”.

In this specification, “at least one of A and B” may refer to “only A”,“only B”, or “both A and B”. In addition, in this specification, theexpression of “at least one of A or B” or “at least one of A and/or B”may be interpreted to be the same as “at least one of A and B”.

Also, in this specification, “at least one of A, B and C” may refer to“only A”, “only B”, “only C”, or “any combination of A, B and C”. Also,“at least one of A, B or C” or “at least one of A, B and/or C” may referto “at least one of A, B and C”.

In addition, parentheses used in the present specification may refer to“for example”. Specifically, when indicated as “control information(PDCCH)”, “PDCCH” may be proposed as an example of “controlinformation”. In other words, “control information” in thisspecification is not limited to “PDCCH”, and “PDDCH” may be proposed asan example of “control information”. In addition, even when indicated as“control information (i.e., PDCCH)”, “PDCCH” may be proposed as anexample of “control information”.

In the present specification, technical features that are individuallydescribed in one drawing may be individually or simultaneouslyimplemented. The term “wireless power”, which will hereinafter be usedin this specification, will be used to refer to an arbitrary form ofenergy that is related to an electric field, a magnetic field, and anelectromagnetic field, which is transferred (or transmitted) from awireless power transmitter to a wireless power receiver without usingany physical electromagnetic conductors. The wireless power may also bereferred to as a wireless power signal, and this may refer to anoscillating magnetic flux that is enclosed by a primary coil and asecondary coil. For example, power conversion for wirelessly chargingdevices including mobile phones, cordless phones, iPods, MP3 players,headsets, and so on, within the system will be described in thisspecification. Generally, the basic principle of the wireless powertransfer technique includes, for example, all of a method oftransferring power by using magnetic coupling, a method of transferringpower by using radio frequency (RF), a method of transferring power byusing microwaves, and a method of transferring power by using ultrasound(or ultrasonic waves).

FIG. 1 is a block diagram of a wireless power system (10) according toan exemplary embodiment of the present disclosure.

Referring to FIG. 1 , the wireless power system (10) include a wirelesspower transmitter (100) and a wireless power receiver (200).

The wireless power transmitter (100) is supplied with power from anexternal power source (S) and generates a magnetic field. The wirelesspower receiver (200) generates electric currents by using the generatedmagnetic field, thereby being capable of wirelessly receiving power.

Additionally, in the wireless power system (10), the wireless powertransmitter (100) and the wireless power receiver (200) may transceive(transmit and/or receive) diverse information that is required for thewireless power transfer. Herein, communication between the wirelesspower transmitter (100) and the wireless power receiver (200) may beperformed (or established) in accordance with any one of an in-bandcommunication, which uses a magnetic field that is used for the wirelesspower transfer (or transmission), and an out-band communication, whichuses a separate communication carrier. Out-band communication may alsobe referred to as out-of-band communication. Hereinafter, out-bandcommunication will be largely described. Examples of out-bandcommunication may include NFC, Bluetooth, Bluetooth low energy (BLE),and the like.

Herein, the wireless power transmitter (100) may be provided as a fixedtype or a mobile (or portable) type. Examples of the fixed transmittertype may include an embedded type, which is embedded in in-door ceilingsor wall surfaces or embedded in furniture, such as tables, an implantedtype, which is installed in out-door parking lots, bus stops, subwaystations, and so on, or being installed in means of transportation, suchas vehicles or trains. The mobile (or portable) type wireless powertransmitter (100) may be implemented as a part of another device, suchas a mobile device having a portable size or weight or a cover of alaptop computer, and so on.

Additionally, the wireless power receiver (200) should be interpreted asa comprehensive concept including diverse home appliances and devicesthat are operated by being wirelessly supplied with power instead ofdiverse electronic devices being equipped with a battery and a powercable. Typical examples of the wireless power receiver (200) may includeportable terminals, cellular phones, smartphones, personal digitalassistants (PDAs), portable media players (PDPs), Wibro terminals,tablet PCs, phablet, laptop computers, digital cameras, navigationterminals, television, electronic vehicles (EVs), and so on.

FIG. 2 is a block diagram of a wireless power system (10) according toanother exemplary embodiment of the present disclosure.

Referring to FIG. 2 , in the wireless power system (10), one wirelesspower receiver (200) or a plurality of wireless power receivers mayexist. Although it is shown in FIG. 1 that the wireless powertransmitter (100) and the wireless power receiver (200) send and receivepower to and from one another in a one-to-one correspondence (orrelationship), as shown in FIG. 2 , it is also possible for one wirelesspower transmitter (100) to simultaneously transfer power to multiplewireless power receivers (200-1, 200-2, . . . , 200-M). Mostparticularly, in case the wireless power transfer (or transmission) isperformed by using a magnetic resonance method, one wireless powertransmitter (100) may transfer power to multiple wireless powerreceivers (200-1, 200-2, . . . , 200-M) by using a synchronizedtransport (or transfer) method or a time-division transport (ortransfer) method.

Additionally, although it is shown in FIG. 1 that the wireless powertransmitter (100) directly transfers (or transmits) power to thewireless power receiver (200), the wireless power system (10) may alsobe equipped with a separate wireless power transceiver, such as a relayor repeater, for increasing a wireless power transport distance betweenthe wireless power transmitter (100) and the wireless power receiver(200). In this case, power is delivered to the wireless powertransceiver from the wireless power transmitter (100), and, then, thewireless power transceiver may transfer the received power to thewireless power receiver (200).

Hereinafter, the terms wireless power receiver, power receiver, andreceiver, which are mentioned in this specification, will refer to thewireless power receiver (200). Also, the terms wireless powertransmitter, power transmitter, and transmitter, which are mentioned inthis specification, will refer to the wireless power transmitter (100).

FIG. 3 a shows an exemplary embodiment of diverse electronic devicesadopting a wireless power transfer system.

As shown in FIG. 3 a , the electronic devices included in the wirelesspower transfer system are sorted in accordance with the amount oftransmitted power and the amount of received power. Referring to FIG. 3, wearable devices, such as smart watches, smart glasses, head mounteddisplays (HMDs), smart rings, and so on, and mobile electronic devices(or portable electronic devices), such as earphones, remote controllers,smartphones, PDAs, tablet PCs, and so on, may adopt a low-power(approximately 5 W or less or approximately 20 W or less) wirelesscharging method.

Small-sized/Mid-sized electronic devices, such as laptop computers,robot vacuum cleaners, TV receivers, audio devices, vacuum cleaners,monitors, and so on, may adopt a mid-power (approximately 50 W or lessor approximately 200 W or less) wireless charging method. Kitchenappliances, such as mixers, microwave ovens, electric rice cookers, andso on, and personal transportation devices (or other electric devices ormeans of transportation), such as powered wheelchairs, powered kickscooters, powered bicycles, electric cars, and so on may adopt ahigh-power (approximately 2 kW or less or approximately 22 kW or less)wireless charging method.

The electric devices or means of transportation, which are describedabove (or shown in FIG. 1 ) may each include a wireless power receiver,which will hereinafter be described in detail. Therefore, theabove-described electric devices or means of transportation may becharged (or recharged) by wirelessly receiving power from a wirelesspower transmitter.

Hereinafter, although the present disclosure will be described based ona mobile device adopting the wireless power charging method, this ismerely exemplary. And, therefore, it shall be understood that thewireless charging method according to the present disclosure may beapplied to diverse electronic devices.

A standard for the wireless power transfer (or transmission) includes awireless power consortium (WPC), an air fuel alliance (AFA), and a powermatters alliance (PMA).

The WPC standard defines a baseline power profile (BPP) and an extendedpower profile (EPP). The BPP is related to a wireless power transmitterand a wireless power receiver supporting a power transfer of 5 W, andthe EPP is related to a wireless power transmitter and a wireless powerreceiver supporting the transfer of a power range greater than 5 W andless than 30 W.

Diverse wireless power transmitters and wireless power receivers eachusing a different power level may be covered by each standard and may besorted by different power classes or categories.

For example, the WPC may categorize (or sort) the wireless powertransmitters and the wireless power receivers as PC-1, PC0, PC1, andPC2, and the WPC may provide a standard document (or specification) foreach power class (PC). The PC-1 standard relates to wireless powertransmitters and receivers providing a guaranteed power of less than 5W. The application of PC-1 includes wearable devices, such as smartwatches.

The PC0 standard relates to wireless power transmitters and receiversproviding a guaranteed power of 5 W. The PC0 standard includes an EPPhaving a guaranteed power ranges that extends to 30 W. Although in-band(IB) communication corresponds to a mandatory communication protocol ofPC0, out-of-band (OB) communication that is used as an optional backupchannel may also be used for PC0. The wireless power receiver may beidentified by setting up an OB flag, which indicates whether or not theOB is supported, within a configuration packet. A wireless powertransmitter supporting the OB may enter an OB handover phase bytransmitting a bit-pattern for an OB handover as a response to theconfiguration packet. The response to the configuration packet maycorrespond to an NAK, an ND, or an 8-bit pattern that is newly defined.The application of the PC0 includes smartphones.

The PC1 standard relates to wireless power transmitters and receiversproviding a guaranteed power ranging from 30 W to 150 W. OB correspondsto a mandatory communication channel for PC1, and IB is used forinitialization and link establishment to OB. The wireless powertransmitter may enter an OB handover phase by transmitting a bit-patternfor an OB handover as a response to the configuration packet. Theapplication of the PC1 includes laptop computers or power tools.

The PC2 standard relates to wireless power transmitters and receiversproviding a guaranteed power ranging from 200 W to 2 kW, and itsapplication includes kitchen appliances.

As described above, the PCs may be differentiated in accordance with therespective power levels. And, information on whether or not thecompatibility between the same PCs is supported may be optional ormandatory. Herein, the compatibility between the same PCs indicates thatpower transfer/reception between the same PCs is possible. For example,in case a wireless power transmitter corresponding to PC x is capable ofperforming charging of a wireless power receiver having the same PC x,it may be understood that compatibility is maintained between the samePCs. Similarly, compatibility between different PCs may also besupported. Herein, the compatibility between different PCs indicatesthat power transfer/reception between different PCs is also possible.For example, in case a wireless power transmitter corresponding to PC xis capable of performing charging of a wireless power receiver having PCy, it may be understood that compatibility is maintained between thedifferent PCs.

The support of compatibility between PCs corresponds to an extremelyimportant issue in the aspect of user experience and establishment ofinfrastructure. Herein, however, diverse problems, which will bedescribed below, exist in maintaining the compatibility between PCs.

In case of the compatibility between the same PCs, for example, in caseof a wireless power receiver using a lap-top charging method, whereinstable charging is possible only when power is continuously transferred,even if its respective wireless power transmitter has the same PC, itmay be difficult for the corresponding wireless power receiver to stablyreceive power from a wireless power transmitter of the power toolmethod, which transfers power non-continuously. Additionally, in case ofthe compatibility between different PCs, for example, in case a wirelesspower transmitter having a minimum guaranteed power of 200 W transferspower to a wireless power receiver having a maximum guaranteed power of5 W, the corresponding wireless power receiver may be damaged due to anovervoltage. As a result, it may be inappropriate (or difficult) to usethe PS as an index/reference standard representing/indicating thecompatibility.

Wireless power transmitters and receivers may provide a very convenientuser experience and interface (UX/UI). That is, a smart wirelesscharging service may be provided, and the smart wireless chargingservice may be implemented based on a UX/UI of a smartphone including awireless power transmitter. For these applications, an interface betweena processor of a smartphone and a wireless charging receiver allows for“drop and play” two-way communication between the wireless powertransmitter and the wireless power receiver.

As an example, a user may experience a smart wireless charging servicein a hotel. When the user enters a hotel room and puts a smartphone on awireless charger in the room, the wireless charger transmits wirelesspower to the smartphone and the smartphone receives wireless power. Inthis process, the wireless charger transmits information on the smartwireless charging service to the smartphone. When it is detected thatthe smartphone is located on the wireless charger, when it is detectedthat wireless power is received, or when the smartphone receivesinformation on the smart wireless charging service from the wirelesscharger, the smartphone enters a state of inquiring the user aboutagreement (opt-in) of supplemental features. To this end, the smartphonemay display a message on a screen in a manner with or without an alarmsound. An example of the message may include the phrase “Welcome to###hotel. Select” Yes” to activate smart charging functions: Yes | NoThanks.” The smartphone receives an input from the user who selects Yesor No Thanks, and performs a next procedure selected by the user. If Yesis selected, the smartphone transmits corresponding information to thewireless charger. The smartphone and the wireless charger perform thesmart charging function together.

The smart wireless charging service may also include receiving WiFicredentials auto-filled. For example, the wireless charger transmits theWiFi credentials to the smartphone, and the smartphone automaticallyinputs the WiFi credentials received from the wireless charger byrunning an appropriate application.

The smart wireless charging service may also include running a hotelapplication that provides hotel promotions or obtaining remotecheck-in/check-out and contact information.

As another example, the user may experience the smart wireless chargingservice in a vehicle. When the user gets in the vehicle and puts thesmartphone on the wireless charger, the wireless charger transmitswireless power to the smartphone and the smartphone receives wirelesspower. In this process, the wireless charger transmits information onthe smart wireless charging service to the smartphone. When it isdetected that the smartphone is located on the wireless charger, whenwireless power is detected to be received, or when the smartphonereceives information on the smart wireless charging service from thewireless charger, the smartphone enters a state of inquiring the userabout checking identity.

In this state, the smartphone is automatically connected to the vehiclevia WiFi and/or Bluetooth. The smartphone may display a message on thescreen in a manner with or without an alarm sound. An example of themessage may include a phrase of “Welcome to your car. Select “Yes” tosynch device with in-car controls: Yes | No Thanks.” Upon receiving theuser's input to select Yes or No Thanks, the smartphone performs a nextprocedure selected by the user. If Yes is selected, the smartphonetransmits corresponding information to the wireless charger. Inaddition, the smartphone and the wireless charger may run an in-vehiclesmart control function together by driving in-vehicleapplication/display software. The user may enjoy the desired music andcheck a regular map location. The in-vehicle applications/displaysoftware may include an ability to provide synchronous access forpassers-by.

As another example, the user may experience smart wireless charging athome. When the user enters the room and puts the smartphone on thewireless charger in the room, the wireless charger transmits wirelesspower to the smartphone and the smartphone receives wireless power. Inthis process, the wireless charger transmits information on the smartwireless charging service to the smartphone. When it is detected thatthe smartphone is located on the wireless charger, when wireless poweris detected to be received, or when the smartphone receives informationon the smart wireless charging service from the wireless charger, thesmartphone enters a state of inquiring the user about agreement (opt-in)of supplemental features. To this end, the smartphone may display amessage on the screen in a manner with or without an alarm sound. Anexample of the message may include a phrase such as “Hi xxx, Would youlike to activate night mode and secure the building?: Yes | No Thanks.”The smartphone receives a user input to select Yes or No Thanks andperforms a next procedure selected by the user. If Yes is selected, thesmartphone transmits corresponding information to the wireless charger.The smartphones and the wireless charger may recognize at least user'spattern and recommend the user to lock doors and windows, turn offlights, or set an alarm.

Hereinafter, ‘profiles’ will be newly defined based on indexes/referencestandards representing/indicating the compatibility. More specifically,it may be understood that by maintaining compatibility between wirelesspower transmitters and receivers having the same ‘profile’, stable powertransfer/reception may be performed, and that power transfer/receptionbetween wireless power transmitters and receivers having different‘profiles’ cannot be performed. The ‘profiles’ may be defined inaccordance with whether or not compatibility is possible and/or theapplication regardless of (or independent from) the power class.

For example, the profile may be sorted into 3 different categories, suchas i) Mobile, ii) Power tool and iii) Kitchen.

For another example, the profile may be sorted into 4 differentcategories, such as i) Mobile, ii) Power tool, iii) Kitchen, and iv)Wearable.

In case of the ‘Mobile’ profile, the PC may be defined as PC0 and/orPC1, the communication protocol/method may be defined as IB and OBcommunication, and the operation frequency may be defined as 87 to 205kHz, and smartphones, laptop computers, and so on, may exist as theexemplary application.

In case of the ‘Power tool’ profile, the PC may be defined as PC1, thecommunication protocol/method may be defined as IB communication, andthe operation frequency may be defined as 87 to 145 kHz, and powertools, and so on, may exist as the exemplary application.

In case of the ‘Kitchen’ profile, the PC may be defined as PC2, thecommunication protocol/method may be defined as NFC-based communication,and the operation frequency may be defined as less than 100 kHz, andkitchen/home appliances, and so on, may exist as the exemplaryapplication.

In the case of power tools and kitchen profiles, NFC communication maybe used between the wireless power transmitter and the wireless powerreceiver. The wireless power transmitter and the wireless power receivermay confirm that they are NFC devices with each other by exchanging WPCNFC data exchange profile format (NDEF).

FIG. 3 b shows an example of a WPC NDEF in a wireless power transfersystem.

Referring to FIG. 3 b , the WPC NDEF may include, for example, anapplication profile field (e.g., 1B), a version field (e.g., 1B), andprofile specific data (e.g., 1B). The application profile fieldindicates whether the corresponding device is i) mobile and computing,ii) power tool, and iii) kitchen, and an upper nibble in the versionfield indicates a major version and a lower nibble indicates a minorversion. In addition, profile-specific data defines content for thekitchen.

In case of the ‘Wearable’ profile, the PC may be defined as PC-1, thecommunication protocol/method may be defined as IB communication, andthe operation frequency may be defined as 87 to 205 kHz, and wearabledevices that are worn by the users, and so on, may exist as theexemplary application.

It may be mandatory to maintain compatibility between the same profiles,and it may be optional to maintain compatibility between differentprofiles.

The above-described profiles (Mobile profile, Power tool profile,Kitchen profile, and Wearable profile) may be generalized and expressedas first to nth profile, and a new profile may be added/replaced inaccordance with the WPC standard and the exemplary embodiment.

In case the profile is defined as described above, the wireless powertransmitter may optionally perform power transfer only to the wirelesspower receiving corresponding to the same profile as the wireless powertransmitter, thereby being capable of performing a more stable powertransfer. Additionally, since the load (or burden) of the wireless powertransmitter may be reduced and power transfer is not attempted to awireless power receiver for which compatibility is not possible, therisk of damage in the wireless power receiver may be reduced.

PC1 of the ‘Mobile’ profile may be defined by being derived from anoptional extension, such as OB, based on PC0. And, the ‘Power tool’profile may be defined as a simply modified version of the PC1 ‘Mobile’profile. Additionally, up until now, although the profiles have beendefined for the purpose of maintaining compatibility between the sameprofiles, in the future, the technology may be evolved to a level ofmaintaining compatibility between different profiles. The wireless powertransmitter or the wireless power receiver may notify (or announce) itsprofile to its counterpart by using diverse methods.

In the AFA standard, the wireless power transmitter is referred to as apower transmitting unit (PTU), and the wireless power receiver isreferred to as a power receiving unit (PRU). And, the PTU is categorizedto multiple classes, as shown in Table 1, and the PRU is categorized tomultiple classes, as shown in Table 2.

TABLE 1 Minimum value Minimum for a maximum category number of supportsupported PTU P_(TX) _(—) _(IN) _(—) _(MAX) requirement devices Class 1 2 W 1x Category 1 1x Category 1 Class 2 10 W 1x Category 3 2x Category2 Class 3 16 W 1x Category 4 2x Category 3 Class 4 33 W 1x Category 5 3xCategory 3 Class 5 50 W 1x Category 6 4x Category 3 Class 6 70 W 1xCategory 7 5x Category 3

TABLE 2 PRU P_(RX) _(—) _(OUT) _(—) _(MAX′) Exemplary applicationCategory 1 TBD Bluetooth headset Category 2 3.5 W Feature phone Category3 6.5 W Smartphone Category 4 13 W Tablet PC, Phablet Category 5 25 WSmall form factor laptop Category 6 37.5 W General laptop Category 7 50W Home appliance

As shown in Table 1, a maximum output power capability of Class n PTUmay be equal to or greater than the P_(TX_IN_MAX) of the correspondingclass. The PRU cannot draw a power that is higher than the power levelspecified in the corresponding category.

FIG. 4 a is a block diagram of a wireless power transfer systemaccording to another exemplary embodiment of the present disclosure.

Referring to FIG. 4 a , the wireless power transfer system (10) includesa mobile device (450), which wirelessly receives power, and a basestation (400), which wirelessly transmits power.

As a device providing induction power or resonance power, the basestation (400) may include at least one of a wireless power transmitter(100) and a system unit (405). The wireless power transmitter (100) maytransmit induction power or resonance power and may control thetransmission. The wireless power transmitter (100) may include a powerconversion unit (110) converting electric energy to a power signal bygenerating a magnetic field through a primary coil (or primary coils),and a communications & control unit (120) controlling the communicationand power transfer between the wireless power receiver (200) in order totransfer power at an appropriate (or suitable) level. The system unit(405) may perform input power provisioning, controlling of multiplewireless power transmitters, and other operation controls of the basestation (400), such as user interface control. The power conversioncircuit 110 may be called a power converter, and thecommunication/control circuit 120 may be called a controller.

The primary coil may generate an electromagnetic field by using analternating current power (or voltage or current). The primary coil issupplied with an alternating current power (or voltage or current) of aspecific frequency, which is being outputted from the power conversionunit (110). And, accordingly, the primary coil may generate a magneticfield of the specific frequency. The magnetic field may be generated ina non-radial shape or a radial shape. And, the wireless power receiver(200) receives the generated magnetic field and then generates anelectric current. In other words, the primary coil wirelessly transmitspower.

In the magnetic induction method, a primary coil and a secondary coilmay have randomly appropriate shapes. For example, the primary coil andthe secondary coil may correspond to copper wire being wound around ahigh-permeability formation, such as ferrite or a non-crystalline metal.The primary coil may also be referred to as a transmitting coil, aprimary core, a primary winding, a primary loop antenna, and so on.Meanwhile, the secondary coil may also be referred to as a receivingcoil, a secondary core, a secondary winding, a secondary loop antenna, apickup antenna, and so on.

In case of using the magnetic resonance method, the primary coil and thesecondary coil may each be provided in the form of a primary resonanceantenna and a secondary resonance antenna. The resonance antenna mayhave a resonance structure including a coil and a capacitor. At thispoint, the resonance frequency of the resonance antenna may bedetermined by the inductance of the coil and a capacitance of thecapacitor. Herein, the coil may be formed to have a loop shape. And, acore may be placed inside the loop. The core may include a physicalcore, such as a ferrite core, or an air core.

The energy transmission (or transfer) between the primary resonanceantenna and the second resonance antenna may be performed by a resonancephenomenon occurring in the magnetic field. When a near fieldcorresponding to a resonance frequency occurs in a resonance antenna,and in case another resonance antenna exists near the correspondingresonance antenna, the resonance phenomenon refers to a highly efficientenergy transfer occurring between the two resonance antennas that arecoupled with one another. When a magnetic field corresponding to theresonance frequency is generated between the primary resonance antennaand the secondary resonance antenna, the primary resonance antenna andthe secondary resonance antenna resonate with one another. And,accordingly, in a general case, the magnetic field is focused toward thesecond resonance antenna at a higher efficiency as compared to a casewhere the magnetic field that is generated from the primary antenna isradiated to a free space. And, therefore, energy may be transferred tothe second resonance antenna from the first resonance antenna at a highefficiency. The magnetic induction method may be implemented similarlyto the magnetic resonance method. However, in this case, the frequencyof the magnetic field is not required to be a resonance frequency.Nevertheless, in the magnetic induction method, the loops configuringthe primary coil and the secondary coil are required to match oneanother, and the distance between the loops should be very close-ranged.

Although it is not shown in the drawing, the wireless power transmitter(100) may further include a communication antenna. The communicationantenna may transmit and/or receive a communication signal by using acommunication carrier apart from the magnetic field communication. Forexample, the communication antenna may transmit and/or receivecommunication signals corresponding to Wi-Fi, Bluetooth, Bluetooth LE,ZigBee, NFC, and so on.

The communications & control unit (120) may transmit and/or receiveinformation to and from the wireless power receiver (200). Thecommunications & control unit (120) may include at least one of an IBcommunication module and an OB communication module.

The IB communication module may transmit and/or receive information byusing a magnetic wave, which uses a specific frequency as its centerfrequency. For example, the communications & control unit (120) mayperform in-band (IB) communication by transmitting communicationinformation on the operating frequency of wireless power transferthrough the primary coil or by receiving communication information onthe operating frequency through the primary coil. At this point, thecommunications & control unit (120) may load information in the magneticwave or may interpret the information that is carried by the magneticwave by using a modulation scheme, such as binary phase shift keying(BPSK), Frequency Shift Keying(FSK) or amplitude shift keying (ASK), andso on, or a coding scheme, such as Manchester coding ornon-return-to-zero level (NZR-L) coding, and so on. By using theabove-described IB communication, the communications & control unit(120) may transmit and/or receive information to distances of up toseveral meters at a data transmission rate of several kbps.

The OB communication module may also perform out-of-band communicationthrough a communication antenna. For example, the communications &control unit (120) may be provided to a near field communication module.Examples of the near field communication module may includecommunication modules, such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee,NFC, and so on.

The communications & control unit (120) may control the overalloperations of the wireless power transmitter (100). The communications &control unit (120) may perform calculation and processing of diverseinformation and may also control each configuration element of thewireless power transmitter (100).

The communications & control unit (120) may be implemented in a computeror a similar device as hardware, software, or a combination of the same.When implemented in the form of hardware, the communications & controlunit (120) may be provided as an electronic circuit performing controlfunctions by processing electrical signals. And, when implemented in theform of software, the communications & control unit (120) may beprovided as a program that operates the communications & control unit(120).

By controlling the operating point, the communications & control unit(120) may control the transmitted power. The operating point that isbeing controlled may correspond to a combination of a frequency (orphase), a duty cycle, a duty ratio, and a voltage amplitude. Thecommunications & control unit (120) may control the transmitted power byadjusting any one of the frequency (or phase), the duty cycle, the dutyratio, and the voltage amplitude. Additionally, the wireless powertransmitter (100) may supply a consistent level of power, and thewireless power receiver (200) may control the level of received power bycontrolling the resonance frequency.

The mobile device (450) includes a wireless power receiver (200)receiving wireless power through a secondary coil, and a load (455)receiving and storing the power that is received by the wireless powerreceiver (200) and supplying the received power to the device.

The wireless power receiver (200) may include a power pick-up unit (210)and a communications & control unit (220). The power pick-up unit (210)may receive wireless power through the secondary coil and may convertthe received wireless power to electric energy. The power pick-up unit(210) rectifies the alternating current (AC) signal, which is receivedthrough the secondary coil, and converts the rectified signal to adirect current (DC) signal. The communications & control unit (220) maycontrol the transmission and reception of the wireless power (transferand reception of power). The power pickup circuit 210 may also be calleda power pickup, and the communication/control circuit 220 may be calleda controller.

The secondary coil may receive wireless power that is being transmittedfrom the wireless power transmitter (100). The secondary coil mayreceive power by using the magnetic field that is generated in theprimary coil. Herein, in case the specific frequency corresponds aresonance frequency, magnetic resonance may occur between the primarycoil and the secondary coil, thereby allowing power to be transferredwith greater efficiency.

Although it is not shown in FIG. 4 a , the communications & control unit(220) may further include a communication antenna. The communicationantenna may transmit and/or receive a communication signal by using acommunication carrier apart from the magnetic field communication. Forexample, the communication antenna may transmit and/or receivecommunication signals corresponding to Wi-Fi, Bluetooth, Bluetooth LE,ZigBee, NFC, and so on.

The communications & control unit (220) may transmit and/or receiveinformation to and from the wireless power transmitter (100). Thecommunications & control unit (220) may include at least one of an IBcommunication module and an OB communication module.

The IB communication module may transmit and/or receive information byusing a magnetic wave, which uses a specific frequency as its centerfrequency. For example, the communications & control unit (220) mayperform IB communication by loading information in the magnetic wave andby transmitting the information through the secondary coil or byreceiving a magnetic wave carrying information through the secondarycoil. At this point, the communications & control unit (120) may loadinformation in the magnetic wave or may interpret the information thatis carried by the magnetic wave by using a modulation scheme, such asbinary phase shift keying (BPSK), Frequency Shift Keying(FSK) oramplitude shift keying (ASK), and so on, or a coding scheme, such asManchester coding or non-return-to-zero level (NZR-L) coding, and so on.By using the above-described IB communication, the communications &control unit (220) may transmit and/or receive information to distancesof up to several meters at a data transmission rate of several kbps.

The OB communication module may also perform out-of-band communicationthrough a communication antenna. For example, the communications &control unit (220) may be provided to a near field communication module.

Examples of the near field communication module may includecommunication modules, such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee,NFC, and so on.

The communications & control unit (220) may control the overalloperations of the wireless power receiver (200). The communications &control unit (220) may perform calculation and processing of diverseinformation and may also control each configuration element of thewireless power receiver (200).

The communications & control unit (220) may be implemented in a computeror a similar device as hardware, software, or a combination of the same.When implemented in the form of hardware, the communications & controlunit (220) may be provided as an electronic circuit performing controlfunctions by processing electrical signals. And, when implemented in theform of software, the communications & control unit (220) may beprovided as a program that operates the communications & control unit(220).

When the communication/control circuit 120 and the communication/controlcircuit 220 are Bluetooth or Bluetooth LE as an OB communication moduleor a short-range communication module, the communication/control circuit120 and the communication/control circuit 220 may each be implementedand operated with a communication architecture as shown in FIG. 4 b.

FIG. 4 b is a diagram illustrating an example of a Bluetoothcommunication architecture to which an embodiment according to thepresent disclosure may be applied.

Referring to FIG. 4 b , (a) of FIG. 4 b shows an example of a protocolstack of Bluetooth basic rate (BR)/enhanced data rate (EDR) supportingGATT, and (b) shows an example of Bluetooth low energy (BLE) protocolstack.

Specifically, as shown in (a) of FIG. 4 b , the Bluetooth BR/EDRprotocol stack may include an upper control stack 460 and a lower hoststack 470 based on a host controller interface (HCI) 18.

The host stack (or host module) 470 refers to hardware for transmittingor receiving a Bluetooth packet to or from a wirelesstransmission/reception module which receives a Bluetooth signal of 2.4GHz, and the controller stack 460 is connected to the Bluetooth moduleto control the Bluetooth module and perform an operation.

The host stack 470 may include a BR/EDR PHY layer 12, a BR/EDR basebandlayer 14, and a link manager layer 16.

The BR/EDR PHY layer 12 is a layer that transmits and receives a 2.4 GHzradio signal, and in the case of using Gaussian frequency shift keying(GFSK) modulation, the BR/EDR PHY layer 12 may transmit data by hopping79 RF channels.

The BR/EDR baseband layer 14 serves to transmit a digital signal,selects a channel sequence for hopping 1400 times per second, andtransmits a time slot with a length of 625 us for each channel.

The link manager layer 16 controls an overall operation (link setup,control, security) of Bluetooth connection by utilizing a link managerprotocol (LMP).

The link manager layer 16 may perform the following functions.

-   -   Performs ACL/SCO logical transport, logical link setup, and        control.    -   Detach: It interrupts connection and informs a counterpart        device about a reason for the interruption.    -   Performs power control and role switch.    -   Performs security (authentication, pairing, encryption)        function.

The host controller interface layer 18 provides an interface between ahost module and a controller module so that a host provides commands anddata to the controller and the controller provides events and data tothe host.

The host stack (or host module, 470) includes a logical link control andadaptation protocol (L2CAP) 21, an attribute protocol 22, a genericattribute profile (GATT) 23, a generic access profile (GAP) 24, and aBR/EDR profile 25.

The logical link control and adaptation protocol (L2CAP) 21 may provideone bidirectional channel for transmitting data to a specific protocolor profile.

The L2CAP 21 may multiplex various protocols, profiles, etc., providedfrom upper Bluetooth.

L2CAP of Bluetooth BR/EDR uses dynamic channels, supports protocolservice multiplexer, retransmission, streaming mode, and providessegmentation and reassembly, per-channel flow control, and errorcontrol.

The generic attribute profile (GATT) 23 may be operable as a protocolthat describes how the attribute protocol 22 is used when services areconfigured. For example, the generic attribute profile 23 may beoperable to specify how ATT attributes are grouped together intoservices and may be operable to describe features associated withservices.

Accordingly, the generic attribute profile 23 and the attributeprotocols (ATT) 22 may use features to describe device's state andservices, how features are related to each other, and how they are used.

The attribute protocol 22 and the BR/EDR profile 25 define a service(profile) using Bluetooth BR/EDR and an application protocol forexchanging these data, and the generic access profile (GAP) 24 definesdevice discovery, connectivity, and security level.

As shown in (b) of FIG. 4 b , the Bluetooth LE protocol stack includes acontroller stack 480 operable to process a wireless device interfaceimportant in timing and a host stack 490 operable to process high leveldata.

First, the controller stack 480 may be implemented using a communicationmodule that may include a Bluetooth wireless device, for example, aprocessor module that may include a processing device such as amicroprocessor.

The host stack 490 may be implemented as a part of an OS running on aprocessor module or as an instantiation of a package on the OS.

In some cases, the controller stack and the host stack may be run orexecuted on the same processing device in a processor module.

The controller stack 480 includes a physical layer (PHY) 32, a linklayer 34, and a host controller interface 36.

The physical layer (PHY, wireless transmission/reception module) 32 is alayer that transmits and receives a 2.4 GHz radio signal and usesGaussian frequency shift keying (GFSK) modulation and a frequencyhopping scheme including 40 RF channels.

The link layer 34, which serves to transmit or receive Bluetoothpackets, creates connections between devices after performingadvertising and scanning functions using 3 advertising channels andprovides a function of exchanging data packets of up to 257 bytesthrough 37 data channels.

The host stack includes a generic access profile (GAP) 45, a logicallink control and adaptation protocol (L2CAP, 41), a security manager(SM) 42, and an attribute protocol (ATT) 43, a generic attribute profile(GATT) 44, a generic access profile 45, and an LE profile 46. However,the host stack 490 is not limited thereto and may include variousprotocols and profiles.

The host stack multiplexes various protocols, profiles, etc., providedfrom upper Bluetooth using L2CAP.

First, the logical link control and adaptation protocol (L2CAP) 41 mayprovide one bidirectional channel for transmitting data to a specificprotocol or profile.

The L2CAP 41 may be operable to multiplex data between higher layerprotocols, segment and reassemble packages, and manage multicast datatransmission.

In Bluetooth LE, three fixed channels (one for signaling CH, one forsecurity manager, and one for attribute protocol) are basically used.Also, a dynamic channel may be used as needed.

Meanwhile, a basic channel/enhanced data rate (BR/EDR) uses a dynamicchannel and supports protocol service multiplexer, retransmission,streaming mode, and the like.

The security manager (SM) 42 is a protocol for authenticating devicesand providing key distribution.

The attribute protocol (ATT) 43 defines a rule for accessing data of acounterpart device in a server-client structure. The ATT has thefollowing 6 message types (request, response, command, notification,indication, confirmation).

{circle around (1)} Request and Response message: A request message is amessage for requesting specific information from the client device tothe server device, and the response message is a response message to therequest message, which is a message transmitted from the server deviceto the client device.

{circle around (2)} Command message: It is a message transmitted fromthe client device to the server device in order to indicate a command ofa specific operation. The server device does not transmit a responsewith respect to the command message to the client device.

{circle around (3)} Notification message: It is a message transmittedfrom the server device to the client device in order to notify an event,or the like. The client device does not transmit a confirmation messagewith respect to the notification message to the server device.

{circle around (4)} Indication and confirmation message: It is a messagetransmitted from the server device to the client device in order tonotify an event, or the like. Unlike the notification message, theclient device transmits a confirmation message regarding the indicationmessage to the server device.

In the present disclosure, when the GATT profile using the attributeprotocol (ATT) 43 requests long data, a value regarding a data length istransmitted to allow a client to clearly know the data length, and acharacteristic value may be received from a server by using a universalunique identifier (UUID).

The generic access profile (GAP) 45, a layer newly implemented for theBluetooth LE technology, is used to select a role for communicationbetween Bluetooth LED devices and to control how a multi-profileoperation takes place.

Also, the generic access profile (GAP) 45 is mainly used for devicediscovery, connection generation, and security procedure part, defines ascheme for providing information to a user, and defines types ofattributes as follows.

{circle around (1)} Service: It defines a basic operation of a device bya combination of behaviors related to data

{circle around (2)} Include: It defines a relationship between services

{circle around (3)} Characteristics: It is a data value used in a server

{circle around (4)} Behavior: It is a format that may be read by acomputer defined by a UUID (value type).

The LE profile 46, including profiles dependent upon the GATT, is mainlyapplied to a Bluetooth LE device. The LE profile 46 may include, forexample, Battery, Time, FindMe, Proximity, Time, Object DeliveryService, and the like, and details of the GATT-based profiles are asfollows.

{circle around (1)} Battery: Battery information exchanging method

{circle around (2)} Time: Time information exchanging method

{circle around (3)} FindMe: Provision of alarm service according todistance

{circle around (4)} Proximity: Battery information exchanging method

{circle around (5)} Time: Time information exchanging method

The generic attribute profile (GATT) 44 may operate as a protocoldescribing how the attribute protocol (ATT) 43 is used when services areconfigured. For example, the GATT 44 may operate to define how ATTattributes are grouped together with services and operate to describefeatures associated with services.

Thus, the GATT 44 and the ATT 43 may use features in order to describestatus and services of a device and describe how the features arerelated and used.

Hereinafter, procedures of the Bluetooth low energy (BLE) technologywill be briefly described.

The BLE procedure may be classified as a device filtering procedure, anadvertising procedure, a scanning procedure, a discovering procedure,and a connecting procedure.

Device Filtering Procedure

The device filtering procedure is a method for reducing the number ofdevices performing a response with respect to a request, indication,notification, and the like, in the controller stack.

When requests are received from all the devices, it is not necessary torespond thereto, and thus, the controller stack may perform control toreduce the number of transmitted requests to reduce power consumption.

An advertising device or scanning device may perform the devicefiltering procedure to limit devices for receiving an advertisingpacket, a scan request or a connection request.

Here, the advertising device refers to a device transmitting anadvertising event, that is, a device performing an advertisement and isalso termed an advertiser.

The scanning device refers to a device performing scanning, that is, adevice transmitting a scan request.

In the BLE, in a case in which the scanning device receives someadvertising packets from the advertising device, the scanning deviceshould transmit a scan request to the advertising device.

However, in a case in which a device filtering procedure is used so ascan request transmission is not required, the scanning device maydisregard the advertising packets transmitted from the advertisingdevice.

Even in a connection request process, the device filtering procedure maybe used. In a case in which device filtering is used in the connectionrequest process, it is not necessary to transmit a response with respectto the connection request by disregarding the connection request.

Advertising Procedure

The advertising device performs an advertising procedure to performundirected broadcast to devices within a region.

Here, the undirected broadcast is advertising toward all the devices,rather than broadcast toward a specific device, and all the devices mayscan advertising to make an supplemental information request or aconnection request.

In contrast, directed advertising may make an supplemental informationrequest or a connection request by scanning advertising for only adevice designated as a reception device.

The advertising procedure is used to establish a Bluetooth connectionwith an initiating device nearby.

Or, the advertising procedure may be used to provide periodicalbroadcast of user data to scanning devices performing listening in anadvertising channel.

In the advertising procedure, all the advertisements (or advertisingevents) are broadcast through an advertisement physical channel.

The advertising devices may receive scan requests from listening devicesperforming listening to obtain additional user data from advertisingdevices. The advertising devices transmit responses with respect to thescan requests to the devices which have transmitted the scan requests,through the same advertising physical channels as the advertisingphysical channels in which the scan requests have been received.

Broadcast user data sent as part of advertising packets are dynamicdata, while the scan response data is generally static data.

The advertisement device may receive a connection request from aninitiating device on an advertising (broadcast) physical channel. If theadvertising device has used a connectable advertising event and theinitiating device has not been filtered according to the devicefiltering procedure, the advertising device may stop advertising andenter a connected mode. The advertising device may start advertisingafter the connected mode.

Scanning Procedure

A device performing scanning, that is, a scanning device performs ascanning procedure to listen to undirected broadcasting of user datafrom advertising devices using an advertising physical channel.

The scanning device transmits a scan request to an advertising devicethrough an advertising physical channel in order to request additionaldata from the advertising device. The advertising device transmits ascan response as a response with respect to the scan request, byincluding additional user data which has requested by the scanningdevice through an advertising physical channel.

The scanning procedure may be used while being connected to other BLEdevice in the BLE piconet.

If the scanning device is in an initiator mode in which the scanningdevice may receive an advertising event and initiates a connectionrequest. The scanning device may transmit a connection request to theadvertising device through the advertising physical channel to start aBluetooth connection with the advertising device.

When the scanning device transmits a connection request to theadvertising device, the scanning device stops the initiator modescanning for additional broadcast and enters the connected mode.

Discovering Procedure

Devices available for Bluetooth communication (hereinafter, referred toas “Bluetooth devices”) perform an advertising procedure and a scanningprocedure in order to discover devices located nearby or in order to bediscovered by other devices within a given area.

The discovering procedure is performed asymmetrically. A Bluetoothdevice intending to discover other device nearby is termed a discoveringdevice, and listens to discover devices advertising an advertising eventthat may be scanned. A Bluetooth device which may be discovered by otherdevice and available to be used is termed a discoverable device andpositively broadcasts an advertising event such that it may be scannedby other device through an advertising (broadcast) physical channel.

Both the discovering device and the discoverable device may have alreadybeen connected with other Bluetooth devices in a piconet.

Connecting Procedure

A connecting procedure is asymmetrical, and requests that, while aspecific Bluetooth device is performing an advertising procedure,another Bluetooth device should perform a scanning procedure.

That is, an advertising procedure may be aimed, and as a result, onlyone device may response to the advertising. After a connectableadvertising event is received from an advertising device, a connectingrequest may be transmitted to the advertising device through anadvertising (broadcast) physical channel to initiate connection.

Hereinafter, operational states, that is, an advertising state, ascanning state, an initiating state, and a connection state, in the BLEtechnology will be briefly described.

Advertising State

A link layer (LL) enters an advertising state according to aninstruction from a host (stack). In a case in which the LL is in theadvertising state, the LL transmits an advertising packet data unit(PDU) in advertising events.

Each of the advertising events include at least one advertising PDU, andthe advertising PDU is transmitted through an advertising channel indexin use. After the advertising PDU is transmitted through an advertisingchannel index in use, the advertising event may be terminated, or in acase in which the advertising device may need to secure a space forperforming other function, the advertising event may be terminatedearlier.

Scanning State

The LL enters the scanning state according to an instruction from thehost (stack). In the scanning state, the LL listens to advertisingchannel indices.

The scanning state includes two types: passive scanning and activescanning. Each of the scanning types is determined by the host.

Time for performing scanning or an advertising channel index are notdefined.

During the scanning state, the LL listens to an advertising channelindex in a scan window duration. A scan interval is defined as aninterval between start points of two continuous scan windows.

When there is no collision in scheduling, the LL should listen in orderto complete all the scan intervals of the scan window as instructed bythe host. In each scan window, the LL should scan other advertisingchannel index. The LL uses every available advertising channel index.

In the passive scanning, the LL only receives packets and cannottransmit any packet.

In the active scanning, the LL performs listening in order to be reliedon an advertising PDU type for requesting advertising PDUs andadvertising device-related supplemental information from the advertisingdevice.

Initiating State

The LL enters the initiating state according to an instruction from thehost (stack).

When the LL is in the initiating state, the LL performs listening onadvertising channel indices.

During the initiating state, the LL listens to an advertising channelindex during the scan window interval.

Connection State

When the device performing a connection state, that is, when theinitiating device transmits a CONNECT_REQ PDU to the advertising deviceor when the advertising device receives a CONNECT_REQ PDU from theinitiating device, the LL enters a connection state.

It is considered that a connection is generated after the LL enters theconnection state. However, it is not necessary to consider that theconnection should be established at a point in time at which the LLenters the connection state. The only difference between a newlygenerated connection and an already established connection is a LLconnection supervision timeout value.

When two devices are connected, the two devices play different roles.

An LL serving as a master is termed a master, and an LL serving as aslave is termed a slave. The master adjusts a timing of a connectingevent, and the connecting event refers to a point in time at which themaster and the slave are synchronized.

Hereinafter, packets defined in an Bluetooth interface will be brieflydescribed. BLE devices use packets defined as follows.

Packet Format

The LL has only one packet format used for both an advertising channelpacket and a data channel packet.

Each packet includes four fields of a preamble, an access address, aPDU, and a CRC.

When one packet is transmitted in an advertising physical channel, thePDU may be an advertising channel PDU, and when one packet istransmitted in a data physical channel, the PDU may be a data channelPDU.

Advertising Channel PDU

An advertising channel PDU has a 16-bit header and payload havingvarious sizes.

A PDU type field of the advertising channel PDU included in the heaterindicates PDU types defined in Table 3 below.

TABLE 3 PDU Type Packet Name 0000 ADV_IND 0001 ADV_DIRECT_IND 0010ADV_NONCONN_IND 0011 SCAN_REQ 0100 SCAN_RSP 0101 CONNECT_REQ 0110ADV_SCAN_IND 0111-1111 Reserved

Advertising PDU

The following advertising channel PDU types are termed advertising PDUsand used in a specific event.

ADV_IND: Connectable undirected advertising event

ADV_DIRECT_IND: Connectable directed advertising event

ADV_NONCONN_IND: Unconnectable undirected advertising event

ADV_SCAN_IND: Scannable undirected advertising event

The PDUs are transmitted from the LL in an advertising state, andreceived by the LL in a scanning state or in an initiating state.

Scanning PDU

The following advertising channel DPU types are termed scanning PDUs andare used in a state described hereinafter.

SCAN_REQ: Transmitted by the LL in a scanning state and received by theLL in an advertising state.

SCAN_RSP: Transmitted by the LL in the advertising state and received bythe LL in the scanning state.

Initiating PDU

The following advertising channel PDU type is termed an initiating PDU.

CONNECT_REQ: Transmitted by the LL in the initiating state and receivedby the LL in the advertising state.

Data Channel PDU

The data channel PDU may include a message integrity check (MIC) fieldhaving a 16-bit header and payload having various sizes.

The procedures, states, and packet formats in the BLE technologydiscussed above may be applied to perform the methods proposed in thepresent disclosure.

Referring to FIG. 4 a , the load (455) may correspond to a battery. Thebattery may store energy by using the power that is being outputted fromthe power pick-up unit (210). Meanwhile, the battery is not mandatorilyrequired to be included in the mobile device (450). For example, thebattery may be provided as a detachable external feature. As anotherexample, the wireless power receiver may include an operating means thatmay execute diverse functions of the electronic device instead of thebattery.

As shown in the drawing, although the mobile device (450) is illustratedto be included in the wireless power receiver (200) and the base station(400) is illustrated to be included in the wireless power transmitter(100), in a broader meaning, the wireless power receiver (200) may beidentified (or regarded) as the mobile device (450), and the wirelesspower transmitter (100) may be identified (or regarded) as the basestation (400).

When the communication/control circuit 120 and the communication/controlcircuit 220 include Bluetooth or Bluetooth LE as an OB communicationmodule or a short-range communication module in addition to the IBcommunication module, the wireless power transmitter 100 including thecommunication/control circuit 120 and the wireless power receiver 200including the communication/control circuit 220 may be represented by asimplified block diagram as shown in FIG. 4 c.

FIG. 4 c is a block diagram illustrating a wireless power transfersystem using BLE communication according to an example.

Referring to FIG. 4 c , the wireless power transmitter 100 includes apower conversion circuit 110 and a communication/control circuit 120.The communication/control circuit 120 includes an in-band communicationmodule 121 and a BLE communication module 122.

Meanwhile, the wireless power receiver 200 includes a power pickupcircuit 210 and a communication/control circuit 220. Thecommunication/control circuit 220 includes an in-band communicationmodule 221 and a BLE communication module 222.

In one aspect, the BLE communication modules 122 and 222 perform thearchitecture and operation according to FIG. 4 b . For example, the BLEcommunication modules 122 and 222 may be used to establish a connectionbetween the wireless power transmitter 100 and the wireless powerreceiver 200 and exchange control information and packets necessary forwireless power transfer.

In another aspect, the communication/control circuit 120 may beconfigured to operate a profile for wireless charging. Here, the profilefor wireless charging may be GATT using BLE transmission.

FIG. 4 d is a block diagram illustrating a wireless power transfersystem using BLE communication according to another example.

Referring to FIG. 4 d , the communication/control circuits 120 and 220respectively include only in-band communication modules 121 and 221, andthe BLE communication modules 122 and 222 may be provided to beseparated from the communication/control circuits 120 and 220.

Hereinafter, the coil or coil unit includes a coil and at least onedevice being approximate to the coil, and the coil or coil unit may alsobe referred to as a coil assembly, a coil cell, or a cell.

FIG. 5 is a state transition diagram for describing a wireless powertransfer procedure.

Referring to FIG. 5 , the power transfer (or transfer) from the wirelesspower transmitter to the wireless power receiver according to anexemplary embodiment of the present disclosure may be broadly dividedinto a selection phase (510), a ping phase (520), an identification andconfiguration phase (530), a negotiation phase (540), a calibrationphase (550), a power transfer phase (560), and a renegotiation phase(570).

If a specific error or a specific event is detected when the powertransfer is initiated or while maintaining the power transfer, theselection phase (510) may include a shifting phase (or step)—referencenumerals S502, S504, S508, S510, and S512. Herein, the specific error orspecific event will be specified in the following description.Additionally, during the selection phase (510), the wireless powertransmitter may monitor whether or not an object exists on an interfacesurface. If the wireless power transmitter detects that an object isplaced on the interface surface, the process step may be shifted to theping phase (520). During the selection phase (510), the wireless powertransmitter may transmit an analog ping having a power signal(or apulse) corresponding to an extremely short duration, and may detectwhether or not an object exists within an active area of the interfacesurface based on a current change in the transmitting coil or theprimary coil.

In case an object is sensed (or detected) in the selection phase (510),the wireless power transmitter may measure a quality factor of awireless power resonance circuit (e.g., power transfer coil and/orresonance capacitor). According to the exemplary embodiment of thepresent disclosure, during the selection phase (510), the wireless powertransmitter may measure the quality factor in order to determine whetheror not a foreign object exists in the charging area along with thewireless power receiver. In the coil that is provided in the wirelesspower transmitter, inductance and/or components of the series resistancemay be reduced due to a change in the environment, and, due to suchdecrease, a value of the quality factor may also be decreased. In orderto determine the presence or absence of a foreign object by using themeasured quality factor value, the wireless power transmitter mayreceive from the wireless power receiver a reference quality factorvalue, which is measured in advance in a state where no foreign objectis placed within the charging area. The wireless power transmitter maydetermine the presence or absence of a foreign object by comparing themeasured quality factor value with the reference quality factor value,which is received during the negotiation phase (540). However, in caseof a wireless power receiver having a low reference quality factorvalue—e.g., depending upon its type, purpose, characteristics, and soon, the wireless power receiver may have a low reference quality factorvalue—in case a foreign object exists, since the difference between thereference quality factor value and the measured quality factor value issmall (or insignificant), a problem may occur in that the presence ofthe foreign object cannot be easily determined. Accordingly, in thiscase, other determination factors should be further considered, or thepresent or absence of a foreign object should be determined by usinganother method.

According to another exemplary embodiment of the present disclosure, incase an object is sensed (or detected) in the selection phase (510), inorder to determine whether or not a foreign object exists in thecharging area along with the wireless power receiver, the wireless powertransmitter may measure the quality factor value within a specificfrequency area (e.g., operation frequency area). In the coil that isprovided in the wireless power transmitter, inductance and/or componentsof the series resistance may be reduced due to a change in theenvironment, and, due to such decrease, the resonance frequency of thecoil of the wireless power transmitter may be changed (or shifted). Morespecifically, a quality factor peak frequency that corresponds to afrequency in which a maximum quality factor value is measured within theoperation frequency band may be moved (or shifted).

In the ping phase (520), if the wireless power transmitter detects thepresence of an object, the transmitter activates (or Wakes up) areceiver and transmits a digital ping for identifying whether or not thedetected object corresponds to the wireless power receiver. During theping phase (520), if the wireless power transmitter fails to receive aresponse signal for the digital ping—e.g., a signal intensitypacket—from the receiver, the process may be shifted back to theselection phase (510). Additionally, in the ping phase (520), if thewireless power transmitter receives a signal indicating the completionof the power transfer—e.g., charging complete packet—from the receiver,the process may be shifted back to the selection phase (510).

If the ping phase (520) is completed, the wireless power transmitter mayshift to the identification and configuration phase (530) foridentifying the receiver and for collecting configuration and statusinformation.

In the identification and configuration phase (530), if the wirelesspower transmitter receives an unwanted packet (i.e., unexpected packet),or if the wireless power transmitter fails to receive a packet during apredetermined period of time (i.e., out of time), or if a packettransmission error occurs (i.e., transmission error), or if a powertransfer contract is not configured (i.e., no power transfer contract),the wireless power transmitter may shift to the selection phase (510).

The wireless power transmitter may confirm (or verify) whether or notits entry to the negotiation phase (540) is needed based on aNegotiation field value of the configuration packet, which is receivedduring the identification and configuration phase (530). Based on theverified result, in case a negotiation is needed, the wireless powertransmitter enters the negotiation phase (540) and may then perform apredetermined FOD detection procedure. Conversely, in case a negotiationis not needed, the wireless power transmitter may immediately enter thepower transfer phase (560).

In the negotiation phase (540), the wireless power transmitter mayreceive a Foreign Object Detection (FOD) status packet that includes areference quality factor value. Or, the wireless power transmitter mayreceive an FOD status packet that includes a reference peak frequencyvalue. Alternatively, the wireless power transmitter may receive astatus packet that includes a reference quality factor value and areference peak frequency value. At this point, the wireless powertransmitter may determine a quality coefficient threshold value for FOdetection based on the reference quality factor value. The wirelesspower transmitter may determine a peak frequency threshold value for FOdetection based on the reference peak frequency value.

The wireless power transmitter may detect the presence or absence of anFO in the charging area by using the determined quality coefficientthreshold value for FO detection and the currently measured qualityfactor value (i.e., the quality factor value that was measured beforethe ping phase), and, then, the wireless power transmitter may controlthe transmitted power in accordance with the FO detection result. Forexample, in case the FO is detected, the power transfer may be stopped.However, the present disclosure will not be limited only to this.

The wireless power transmitter may detect the presence or absence of anFO in the charging area by using the determined peak frequency thresholdvalue for FO detection and the currently measured peak frequency value(i.e., the peak frequency value that was measured before the pingphase), and, then, the wireless power transmitter may control thetransmitted power in accordance with the FO detection result. Forexample, in case the FO is detected, the power transfer may be stopped.However, the present disclosure will not be limited only to this.

In case the FO is detected, the wireless power transmitter may return tothe selection phase (510). Conversely, in case the FO is not detected,the wireless power transmitter may proceed to the calibration phase(550) and may, then, enter the power transfer phase (560). Morespecifically, in case the FO is not detected, the wireless powertransmitter may determine the intensity of the received power that isreceived by the receiving end during the calibration phase (550) and maymeasure power loss in the receiving end and the transmitting end inorder to determine the intensity of the power that is transmitted fromthe transmitting end. In other words, during the calibration phase(550), the wireless power transmitter may estimate the power loss basedon a difference between the transmitted power of the transmitting endand the received power of the receiving end. The wireless powertransmitter according to the exemplary embodiment of the presentdisclosure may calibrate the threshold value for the FOD detection byapplying the estimated power loss.

In the power transfer phase (560), in case the wireless powertransmitter receives an unwanted packet (i.e., unexpected packet), or incase the wireless power transmitter fails to receive a packet during apredetermined period of time (i.e., time-out), or in case a violation ofa predetermined power transfer contract occurs (i.e., power transfercontract violation), or in case charging is completed, the wirelesspower transmitter may shift to the selection phase (510).

Additionally, in the power transfer phase (560), in case the wirelesspower transmitter is required to reconfigure the power transfer contractin accordance with a status change in the wireless power transmitter,the wireless power transmitter may shift to the renegotiation phase(570). At this point, if the renegotiation is successfully completed,the wireless power transmitter may return to the power transfer phase(560).

In this embodiment, the calibration step 550 and the power transferphase 560 are divided into separate steps, but the calibration step 550may be integrated into the power transfer phase 560. In this case,operations in the calibration step 550 may be performed in the powertransfer phase 560.

The above-described power transfer contract may be configured based onthe status and characteristic information of the wireless powertransmitter and receiver. For example, the wireless power transmitterstatus information may include information on a maximum amount oftransmittable power, information on a maximum number of receivers thatmay be accommodated, and so on. And, the receiver status information mayinclude information on the required power, and so on.

FIG. 6 shows a power control method according to an exemplary embodimentof the present disclosure.

As shown in FIG. 6 , in the power transfer phase (560), by alternatingthe power transfer and/or reception and communication, the wirelesspower transmitter (100) and the wireless power receiver (200) maycontrol the amount (or size) of the power that is being transferred. Thewireless power transmitter and the wireless power receiver operate at aspecific control point. The control point indicates a combination of thevoltage and the electric current that are provided from the output ofthe wireless power receiver, when the power transfer is performed.

More specifically, the wireless power receiver selects a desired controlpoint, a desired output current/voltage, a temperature at a specificlocation of the mobile device, and so on, and additionally determines anactual control point at which the receiver is currently operating. Thewireless power receiver calculates a control error value by using thedesired control point and the actual control point, and, then, thewireless power receiver may transmit the calculated control error valueto the wireless power transmitter as a control error packet.

Also, the wireless power transmitter may configure/control a newoperating point—amplitude, frequency, and duty cycle—by using thereceived control error packet, so as to control the power transfer.Therefore, the control error packet may be transmitted/received at aconstant time interval during the power transfer phase, and, accordingto the exemplary embodiment, in case the wireless power receiverattempts to reduce the electric current of the wireless powertransmitter, the wireless power receiver may transmit the control errorpacket by setting the control error value to a negative number. And, incase the wireless power receiver intends to increase the electriccurrent of the wireless power transmitter, the wireless power receivertransmit the control error packet by setting the control error value toa positive number. During the induction mode, by transmitting thecontrol error packet to the wireless power transmitter as describedabove, the wireless power receiver may control the power transfer.

In the resonance mode, which will hereinafter be described in detail,the device may be operated by using a method that is different from theinduction mode. In the resonance mode, one wireless power transmittershould be capable of serving a plurality of wireless power receivers atthe same time. However, in case of controlling the power transfer justas in the induction mode, since the power that is being transferred iscontrolled by a communication that is established with one wirelesspower receiver, it may be difficult to control the power transfer ofadditional wireless power receivers. Therefore, in the resonance modeaccording to the present disclosure, a method of controlling the amountof power that is being received by having the wireless power transmittercommonly transfer (or transmit) the basic power and by having thewireless power receiver control its own resonance frequency.Nevertheless, even during the operation of the resonance mode, themethod described above in FIG. 6 will not be completely excluded. And,additional control of the transmitted power may be performed by usingthe method of FIG. 6 .

FIG. 7 is a block diagram of a wireless power transmitter according toanother exemplary embodiment of the present disclosure. This may belongto a wireless power transfer system that is being operated in themagnetic resonance mode or the shared mode. The shared mode may refer toa mode performing a several-for-one (or one-to-many) communication andcharging between the wireless power transmitter and the wireless powerreceiver. The shared mode may be implemented as a magnetic inductionmethod or a resonance method.

Referring to FIG. 7 , the wireless power transmitter (700) may includeat least one of a cover (720) covering a coil assembly, a power adapter(730) supplying power to the power transmitter (740), a powertransmitter (740) transmitting wireless power, and a user interface(750) providing information related to power transfer processing andother related information. Most particularly, the user interface (750)may be optionally included or may be included as another user interface(750) of the wireless power transmitter (700).

The power transmitter (740) may include at least one of a coil assembly(760), an impedance matching circuit (770), an inverter (780), acommunication unit (790), and a control unit (710).

The coil assembly (760) includes at least one primary coil generating amagnetic field. And, the coil assembly (760) may also be referred to asa coil cell.

The impedance matching circuit (770) may provide impedance matchingbetween the inverter and the primary coil(s). The impedance matchingcircuit (770) may generate resonance from a suitable frequency thatboosts the electric current of the primary coil(s). In a multi-coilpower transmitter (740), the impedance matching circuit may additionallyinclude a multiplex that routes signals from the inverter to a subset ofthe primary coils. The impedance matching circuit may also be referredto as a tank circuit.

The impedance matching circuit (770) may include a capacitor, aninductor, and a switching device that switches the connection betweenthe capacitor and the inductor. The impedance matching may be performedby detecting a reflective wave of the wireless power that is beingtransferred (or transmitted) through the coil assembly (760) and byswitching the switching device based on the detected reflective wave,thereby adjusting the connection status of the capacitor or the inductoror adjusting the capacitance of the capacitor or adjusting theinductance of the inductor. In some cases, the impedance matching may becarried out even though the impedance matching circuit (770) is omitted.This specification also includes an exemplary embodiment of the wirelesspower transmitter (700), wherein the impedance matching circuit (770) isomitted.

The inverter (780) may convert a DC input to an AC signal. The inverter(780) may be operated as a half-bridge inverter or a full-bridgeinverter in order to generate a pulse wave and a duty cycle of anadjustable frequency. Additionally, the inverter may include a pluralityof stages in order to adjust input voltage levels.

The communication unit (790) may perform communication with the powerreceiver. The power receiver performs load modulation in order tocommunicate requests and information corresponding to the powertransmitter. Therefore, the power transmitter (740) may use thecommunication unit (790) so as to monitor the amplitude and/or phase ofthe electric current and/or voltage of the primary coil in order todemodulate the data being transmitted from the power receiver.

Additionally, the power transmitter (740) may control the output powerto that the data may be transferred through the communication unit (790)by using a Frequency Shift Keying (FSK) method, and so on.

The control unit (710) may control communication and power transfer (ordelivery) of the power transmitter (740). The control unit (710) maycontrol the power transfer by adjusting the above-described operatingpoint. The operating point may be determined by, for example, at leastany one of the operation frequency, the duty cycle, and the inputvoltage.

The communication unit (790) and the control unit (710) may each beprovided as a separate unit/device/chipset or may be collectivelyprovided as one unit/device/chipset.

FIG. 8 shows a wireless power receiver according to another exemplaryembodiment of the present disclosure. This may belong to a wirelesspower transfer system that is being operated in the magnetic resonancemode or the shared mode.

Referring to FIG. 8 , the wireless power receiver (800) may include atleast one of a user interface (820) providing information related topower transfer processing and other related information, a powerreceiver (830) receiving wireless power, a load circuit (840), and abase (850) supporting and covering the coil assembly. Most particularly,the user interface (820) may be optionally included or may be includedas another user interface (820) of the wireless power receiver (800).

The power receiver (830) may include at least one of a power converter(860), an impedance matching circuit (870), a coil assembly (880), acommunication unit (890), and a control unit (810).

The power converter (860) may convert the AC power that is received fromthe secondary coil to a voltage and electric current that are suitablefor the load circuit. According to an exemplary embodiment, the powerconverter (860) may include a rectifier. The rectifier may rectify thereceived wireless power and may convert the power from an alternatingcurrent (AC) to a direct current (DC). The rectifier may convert thealternating current to the direct current by using a diode or atransistor, and, then, the rectifier may smooth the converted current byusing the capacitor and resistance. Herein, a full-wave rectifier, ahalf-wave rectifier, a voltage multiplier, and so on, that areimplemented as a bridge circuit may be used as the rectifier.Additionally, the power converter may adapt a reflected impedance of thepower receiver.

The impedance matching circuit (870) may provide impedance matchingbetween a combination of the power converter (860) and the load circuit(840) and the secondary coil. According to an exemplary embodiment, theimpedance matching circuit may generate a resonance of approximately 100kHz, which may reinforce the power transfer. The impedance matchingcircuit (870) may include a capacitor, an inductor, and a switchingdevice that switches the combination of the capacitor and the inductor.The impedance matching may be performed by controlling the switchingdevice of the circuit that configured the impedance matching circuit(870) based on the voltage value, electric current value, power value,frequency value, and so on, of the wireless power that is beingreceived. In some cases, the impedance matching may be carried out eventhough the impedance matching circuit (870) is omitted. Thisspecification also includes an exemplary embodiment of the wirelesspower receiver (200), wherein the impedance matching circuit (870) isomitted.

The coil assembly (880) includes at least one secondary coil, and,optionally, the coil assembly (880) may further include an elementshielding the metallic part of the receiver from the magnetic field.

The communication unit (890) may perform load modulation in order tocommunicate requests and other information to the power transmitter.

For this, the power receiver (830) may perform switching of theresistance or capacitor so as to change the reflected impedance.

The control unit (810) may control the received power. For this, thecontrol unit (810) may determine/calculate a difference between anactual operating point and a target operating point of the powerreceiver (830). Thereafter, by performing a request for adjusting thereflected impedance of the power transmitter and/or for adjusting anoperating point of the power transmitter, the difference between theactual operating point and the target operating point may beadjusted/reduced. In case of minimizing this difference, an optimalpower reception may be performed.

The communication unit (890) and the control unit (810) may each beprovided as a separate device/chipset or may be collectively provided asone device/chipset.

FIG. 9 shows a communication frame structure according to an embodiment.This may be a communication frame structure in a shared mode.

Referring to FIG. 9 , in the shared mode, different types of frames maybe used together. For example, in the shared mode, a slotted framehaving a plurality of slots as shown in (A) and a free format framehaving no specific shape as shown in (B) may be used. More specifically,the slot frame is a frame for transmitting short data packets from thewireless power receiver 200 to the wireless power transmitter 100, sincethe free-form frame does not have a plurality of slots, it may be aframe in which long data packets can be transmitted.

Meanwhile, the slot frame and the free-form frame may be changed tovarious names by those skilled in the art. For example, a slot frame maybe changed to a channel frame, a free-form frame may be changed to amessage frame, and the like.

More specifically, the slot frame may include a sync pattern indicatingthe start of a slot, a measurement slot, 9 slots, and an additional syncpattern having the same time interval prior to each of the 9 slots.

Here, the additional sync pattern is a sync pattern different from thesync pattern indicating the start of the frame described above. Morespecifically, the additional sync pattern may not indicate the start ofa frame, but may indicate information related to adjacent slots (i.e.,two consecutive slots located on both sides of the sync pattern).

A sync pattern may be positioned between two consecutive slots among thenine slots. In this case, the sync pattern may provide informationrelated to the two consecutive slots.

Also, the nine slots and the sync patterns provided prior to each of thenine slots may have the same time interval. For example, the nine slotsmay have a time interval of 50 ms. Also, the nine sync patterns may havea time length of 50 ms.

Meanwhile, a free-form frame as shown in (B) may not have a specificshape other than a sync pattern indicating the start of the frame and ameasurement slot. That is, the free-form frame is for performing adifferent role from the slot frame, for example, performingcommunication of long data packets (e.g., additional owner informationpackets) between the wireless power transmitter and the wireless powerreceiver, or in the wireless power transmitter consisting of a pluralityof coils, it may be used for a role of selecting any one of theplurality of coils.

Hereinafter, a sync pattern included in each frame will be described inmore detail with drawings.

FIG. 10 is a structure of a sync pattern according to an exemplaryembodiment.

Referring to FIG. 10 , the sync pattern can be composed of preamble,start bit, response field, type field, info field and parity bit. InFIG. 10 , the start bit is shown as ZERO.

More specifically, the preamble consists of consecutive bits, and all ofthem may be set to 0. That is, the preamble may be bits for matching thetime length of the sync pattern.

The number of bits constituting the preamble may depend on the operatingfrequency so that the length of the sync pattern is closest to 50 ms,but within a range that does not exceed 50 ms. For example, when theoperating frequency is 100 kHz, the sync pattern may be composed of twopreamble bits, and when the operating frequency is 105 kHz, the syncpattern may be composed of three preamble bits.

The start bit is a bit following the preamble and may mean ZERO. Thezero may be a bit indicating the type of the sync pattern. Here, thetypes of sync patterns may include frame sync including frame-relatedinformation and slot sync including slot information. That is, the syncpattern is located between successive frames, it is a frame syncindicating the start of a frame, or located between consecutive slotsamong a plurality of slots constituting a frame, it may be a slot sinkincluding information related to the successive slots.

For example, when the zero is 0, it means that the corresponding slot isslot sync located between the slots, and when it is 1, it can mean thatthe corresponding sync pattern is frame sync located between the frames.

The parity bit is the last bit of the sync pattern and may indicateinformation on the number of bits constituting the data fields (i.e.,the response field, the type field, and the information field) of thesync pattern. For example, the previous parity bit may be 1 when thenumber of bits constituting the data fields of the sync pattern is aneven number, and 0 in other cases (i.e., an odd number).

The response field may include response information of the wirelesspower transmitter for communication with the wireless power receiver ina slot before the sync pattern. For example, the response field may have‘00’ when communication with the wireless power receiver is notdetected. Also, the response field may have ‘01’ when a communicationerror is detected in communication with the wireless power receiver. Thecommunication error may be a case in which two or more wireless powerreceivers attempt to access one slot, and a collision occurs between twoor more wireless power receivers.

Also, the response field may include information indicating whether adata packet has been correctly received from the wireless powerreceiver. More specifically, when the wireless power transmitter deniesthe data packet, the response field may be “10” (10-not acknowledge,NAK), when the wireless power transmitter confirms the data packet, itmay be “11” (11-acknowledge, ACK).

The type field may indicate the type of the sync pattern. Morespecifically, the type field may have ‘1’ indicating frame sync when thesync pattern is the first sync pattern of the frame (i.e., the firstsync pattern of the frame, which is located before the measurementslot).

Also, in the slot frame, when the sync pattern is not the first syncpattern of the frame, the type field may have ‘0’ indicating slot sync.

Also, the meaning of the value of the information field may bedetermined according to the type of the sync pattern indicated by thetype field. For example, when the type field is 1 (i.e., indicatingframe sync), the meaning of the information field may indicate the typeof frame. That is, the information field may indicate whether thecurrent frame is a slotted frame or a free-format frame. For example,when the information field is ‘00’, it may indicate a slot frame, andwhen the information field is ‘01’, it may indicate a free-form frame.

On the other hand, when the type field is 0 (i.e., slot sync), theinformation field may indicate the state of the next slot located afterthe sync pattern. More specifically, when the next slot is a slotallocated to a specific wireless power receiver, the information fieldhas ‘00’, in the case of a locked slot for a specific wireless powerreceiver to use temporarily, it has ‘01’, alternatively, when anywireless power receiver is a freely usable slot, it may have ‘10’.

FIG. 11 illustrates operation states of a wireless power transmitter anda wireless power receiver in a shared mode according to an embodiment.

Referring to FIG. 11 , a wireless power receiver operating in sharedmode, it can operate in any one of the states of Selection Phase (1100),Introduction Phase 1110, Configuration Phase (1120), Negotiation Phase1130 and Power Transfer Phase (1140).

First, the wireless power transmitter according to an embodiment maytransmit a wireless power signal to detect the wireless power receiver.That is, the process of detecting the wireless power receiver using thewireless power signal may be referred to as analog ping.

Meanwhile, the wireless power receiver receiving the wireless powersignal may enter the selection phase 1100. As described above, thewireless power receiver entering the selection phase 1100 may detect thepresence of an FSK signal on the wireless power signal.

That is, the wireless power receiver may perform communication in eitherthe exclusive mode or the shared mode according to the presence of theFSK signal.

More specifically, the wireless power receiver operates in a shared modewhen the FSK signal is included in the wireless power signal, otherwise,it can operate in exclusive mode.

When the wireless power receiver operates in the shared mode, thewireless power receiver may enter an introduction phase 1110. In orderto transmit a control information packet (CI, Control Informationpacket) in the configuration phase, negotiation phase and power transferphase, in the introduction phase 1110, the wireless power receiver maytransmit a control information packet to the wireless power transmitter.The control information packet may have a header and control-relatedinformation. For example, the control information packet may have aheader of 0×53.

In the introduction phase 1110, the wireless power receiver attempts torequest a free slot to transmit a control information (CI) packet overthe following configuration, negotiation, and power transfer phases. Atthis time, the wireless power receiver selects a free slot and transmitsthe first CI packet. If the wireless power transmitter responds with ACKto the CI packet, the wireless power transmitter enters theconfiguration phase. If the wireless power transmitter responds withNAK, another wireless power receiver is in the process of configuringand negotiating. In this case, the wireless power receiver retries therequest for a free slot.

If the wireless power receiver receives an ACK in response to the CIpacket, the wireless power receiver determines the position of a privateslot in the frame by counting the remaining slot sinks up to the firstframe sink. In all subsequent slot-based frames, the wireless powerreceiver transmits the CI packet through the corresponding slot.

If the wireless power transmitter allows the wireless power receiver toproceed to the configuration phase, the wireless power transmitterprovides a series of locked slots for exclusive use of the wirelesspower receiver. This ensures that the wireless power receiver proceedsthrough the configuration phase without conflicts.

The wireless power receiver transmits sequences of data packets such astwo identification data packets (IDHI and IDLO) using a lock slot. Aftercompleting this step, the wireless power receiver enters the negotiationphase. In the negotiation phase, the wireless power transmittercontinues to provide a lock slot for exclusive use to the wireless powerreceiver. This ensures that the wireless power receiver proceeds withthe negotiation phase without collision.

The wireless power receiver transmits one or more negotiation datapackets using the corresponding lock slot, it may be mixed with privatedata packets. Eventually, the sequence ends with a specific request(SRQ) packet. When the sequence is complete, the wireless power receiverenters the power transmission phase, and the wireless power transmitterstops providing the lock slot.

In the power transfer phase, the wireless power receiver transmits theCI packet using the allocated slot and receives power. The wirelesspower receiver may include a regulator circuit. The regulator circuitmay be included in the communication/control circuit. The wireless powerreceiver may self-regulate the reflection impedance of the wirelesspower receiver through a regulator circuit. In other words, the wirelesspower receiver may adjust the reflected impedance in order to transmitthe amount of power required by the external load. This can preventexcessive power reception and overheating.

In the shared mode, since the wireless power transmitter may not performpower adjustment in response to the received CI packet (according to theoperation mode), in this case, control to prevent an overvoltage statemay be required.

As described in FIGS. 5 and 11 , etc., the wireless power transmitterand the wireless power receiver enter a negotiation phase (NegotiationPhase) through a ping phase and a configuration phase, or after goingthrough the ping phase, the configuration phase, and the negotiationphase, the power transfer phase can be entered and then there-negotiation phase can be entered.

In the ping phase, the wireless power transmitter identifies thewireless power receiver by sending a digital ping. In addition, thewireless power transmitter may perform foreign object detection beforepower transfer to determine whether a foreign object exists in anoperating volume. The wireless power receiver receiving the digital pingtransmits a signal strength data packet (SIG) to the wireless powertransmitter, the wireless power transmitter receiving the SIG from thewireless power receiver may identify that the wireless power receiver islocated in an operating volume.

In the configuration phase (or identification and configuration phase),the wireless power receiver transmits its identification information tothe wireless power transmitter, the wireless power receiver and thewireless power transmitter may establish a baseline power transfercontract. The wireless power receiver may transmit an identificationdata packet (ID) and an extended identification data packet (XID) to thewireless power transmitter to identify itself, a power control hold-offdata packet (PCH) and a configuration data packet (CFG) may betransmitted to the wireless power transmitter for a power transmissioncontract.

FIG. 12 is a diagram illustrating a message field of a configurationpacket (CFG) of a wireless power receiver according to an embodiment.

The configuration packet (CFG) according to an embodiment may have aheader value of 0×51 and, referring to FIG. 12 , may include a 5-bytemessage field.

Referring to FIG. 12 , a 1-bit authentication (AI) flag and a 1-bitout-of-band (OB) flag may be included in the message field of theconfiguration packet (CFG).

The authentication flag AI indicates whether the wireless power receiversupports the authentication function. For example, if the value of theauthentication flag AI is ‘1’, it indicates that the wireless powerreceiver supports an authentication function or operates as anauthentication initiator, if the value of the authentication flag AI is‘0’, it may indicate that the wireless power receiver does not supportthe authentication function or cannot operate as an authenticationinitiator.

The out-band (OB) flag indicates whether the wireless power receiversupports out-band communication. For example, if the value of theout-band (OB) flag is ‘1’, the wireless power receiver instructsout-band communication, if the value of the out-band (OB) flag is ‘0’,it may indicate that the wireless power receiver does not supportout-band communication.

In the configuration phase, the wireless power transmitter receives theconfiguration packet (CFG) of the wireless power receiver, and can checkwhether the wireless power receiver supports the authentication functionand whether out-band communication is supported.

On the other hand, in the negotiation phase or renegotiation phase,Power Transfer Contract related to the reception/transmission ofwireless power between the wireless power receiver and the wirelesspower transmitter is expanded or changed, or a renewal of the powertransfer contract is made that adjusts at least some of the elements ofthe power transfer contract, or exchange of information for establishingout-band communication may be performed.

In the negotiation phase, the wireless power receiver may receive anidentification data packet (ID) and a capabilities data packet (CAP) ofthe wireless power transmitter using a general request data packet(GRQ).

The general request packet (GRQ) may have a header value of 0×07 and mayinclude a 1-byte message field. The message field of the general requestpacket (GRQ) may include a header value of a data packet that thewireless power receiver requests from the wireless power transmitterusing the GRQ packet. For example, when the wireless power receiverrequests the ID packet of the wireless power transmitter using the GRQpacket, the wireless power receiver transmits the general request packet(GRQ/id) including the header value (0×30) of the ID packet of thewireless power transmitter in the message field of the general requestpacket (GRQ).

In the negotiation phase or renegotiation phase, the wireless powerreceiver may transmit a GRQ packet (GRQ/id) requesting an ID packet ofthe wireless power transmitter to the wireless power transmitter.

The wireless power transmitter receiving the GRQ/id may transmit the IDpacket to the wireless power receiver. The ID packet of the wirelesspower transmitter includes information on the Manufacturer Code. The IDpacket including information on the Manufacturer Code allows themanufacturer of the wireless power transmitter to be identified.

In the negotiation phase or renegotiation phase, the wireless powerreceiver may transmit a GRQ packet (GRQ/cap) requesting a capabilitypacket (CAP) of the wireless power transmitter to the wireless powertransmitter. The message field of the GRQ/cap may include a header value(0×31) of the capability packet (CAP).

The wireless power transmitter receiving the GRQ/cap may transmit acapability packet (CAP) to the wireless power receiver.

FIG. 13 is a diagram illustrating a message field of a capability packet(CAP) of a wireless power transmitter according to an embodiment.

A capability packet (CAP) according to an embodiment may have a headervalue of 0×31, and referring to FIG. 13 , may include a message field of3 bytes.

Referring to FIG. 13 , a 1-bit authentication (AR) flag and a 1-bitout-of-band (OB) flag may be included in the message field of thecapability packet (CAP).

The authentication flag AR indicates whether the wireless powertransmitter supports the authentication function. For example, if thevalue of the authentication flag AR is ‘1’, it indicates that thewireless power transmitter supports an authentication function or canoperate as an authentication responder, if the value of theauthentication flag AR is ‘0’, it may indicate that the wireless powertransmitter does not support the authentication function or cannotoperate as an authentication responder.

The out-band (OB) flag indicates whether the wireless power transmittersupports out-band communication. For example, if the value of theout-band (OB) flag is ‘1’, the wireless power transmitter indicatesout-band communication, if the value of the out-band (OB) flag is ‘0’,it may indicate that the wireless power transmitter does not supportout-band communication.

In the negotiation phase, the wireless power receiver receives thecapability packet (CAP) of the wireless power transmitter, and can checkwhether the wireless power transmitter supports the authenticationfunction and whether out-band communication is supported.

Also, in the negotiation phase or renegotiation phase, the wirelesspower receiver may renew elements of a power transfer contract relatedto power to be provided in a power transfer phase using a specificrequest data packet (SRQ), it can end the negotiation phase or therenegotiation phase.

In the power transfer phase, the wireless power transmitter and thewireless power receiver may transmit/receive wireless power based on apower transfer contract. The wireless power transmitter and the wirelesspower receiver can control the amount of transmitted power by performingcommunication along with power transmission/reception. The wirelesspower transmitter and the wireless power receiver transmit/receivewireless power in a low-power mode (for example, 5 W or less) untilauthentication of the wireless power transmitter and/or the wirelesspower receiver succeeds, after authentication of the wireless powertransmitter and/or the wireless power receiver is successful, wirelesspower transmission/reception may be performed in a high power mode(e.g., equal to or greater than 5 W).

Since other details of the ping phase, the configuration phase, and thenegotiation phase have been described in FIGS. 5 and 11 , additionaldescriptions thereof will be omitted.

Hereinafter, authentication between the wireless power transmitter andthe wireless power receiver will be described.

A wireless power transmission system using in-band communication can useUSB-C authentication. The authentication may include authentication ofthe wireless power transmitter by the wireless power receiver andauthentication of the wireless power receiver by the wireless powertransmitter.

As described above, the wireless power receiver may inform the wirelesspower transmitter whether the authentication function is supported byusing the configuration packet (CFG), the wireless power transmitter mayinform the wireless power receiver whether the authentication functionis supported by using a capability packet (CAP).

The wireless power transmitter and the wireless power receiver mayperform an authentication protocol in a negotiation phase or a powertransfer phase.

A message used in an authentication protocol is called an authenticationmessage. The authentication message is used to carry information relatedto authentication. There are two types of authentication messages. Oneis an authentication request and the other is an authenticationresponse. The authentication request is sent by the authenticationinitiator, and the authentication response is sent by the authenticationresponder. The wireless power transmitter and the receiver may beauthentication initiators or authentication responders. For example,when the wireless power transmitter is the authentication initiator, thewireless power receiver becomes the authentication responder, when thewireless power receiver is the authentication initiator, the wirelesspower transmitter becomes the authentication responder.

The authentication request message includes GET_DIGESTS (i.e. 4 bytes),GET_CERTIFICATE (i.e. 8 bytes), and CHALLENGE (i.e. 36 bytes).

The authentication response message includes DIGESTS (i.e. 4+32 bytes),CERTIFICATE (i.e. 4+Certificate Chain (3×512 bytes)=1540 bytes),CHALLENGE_AUTH (i.e. 168 bytes), ERROR (i.e. 4 bytes).

The authentication initiator initiates the authentication protocol bysending GET_DIGEST to the authentication responder and requests DIGEST.The authentication responder that receives GET_DIGEST sends DIGEST tothe authentication responder.

The authentication initiator that has received DIGEST checks whether thedigest and public key of the authentication responder are cached inmemory, if the digest and public key are cached, CHALLENGE can be sentto the authentication responder without sending GET_CERTIFICATE. Theauthentication responder that has received CHALLENGE″ sendsCHALLENGE_AUTH to the authentication initiator, the authenticationinitiator may finally check whether the authentication responder isauthenticated based on the received CHALLENGE_AUTH.

If the digest and public key are not cached, the authenticationinitiator requests the certificate by sending GET_CERTIFICATE to theauthentication responder, authentication responder that has receivedGET_CERTIFICATE sends CERTIFICATE. Authentication initiator that hasreceived CERTIFICATE sends CHALLENGE to the authentication responder,authentication responder that has received CHALLENGE″ sendsCHALLENGE_AUTH to the authentication initiator, the authenticationinitiator may finally check whether the authentication responder isauthenticated based on the received CHALLENGE_AUTH.

According to the current Qi specification of a wireless power consortium(WPC), the above-described authentication message istransmitted/received using in-band communication. In in-bandcommunication, the wireless power receiver transmits a message using amodulation method of amplitude shift keying (ASK), the wireless powertransmitter transmits a message using a modulation method of frequencyshift keying (FSK).

However, the FSK method can transmit data at a maximum rate of 200 bpsat an operating frequency of 100 kHz, and the ASK method can transmitdata at a rate of about 2 kbps.

Among authentication response messages, CERTIFICATE may exceed 1000bytes, and CHALLENGE_AUTH may exceed 100 bytes. When the wireless powertransmitter operates as an authentication responder, when sendingCERTIFICATE or CHALLENGE_AUTH using FSK modulation method, it takes asignificant amount of time, and it may take as long as a few minutes ormore to complete the authentication protocol.

In addition, the wireless power receiver should periodically transmit acontrol error data packet (CE) including information on a differencebetween an actual operating point and a target operating point andreceived power data packet (RP) including information on the receivedpower value for wireless power control.

However, in the process of transmitting/receiving an authenticationmessage through in-band communication using the ASK or FSK modulationmethod, the transmission period of the CE and/or RP may not be kept dueto the speed limit of the ASK or FSK modulation method.

On the other hand, out-band communication has a faster data transmissionrate than in-band communication. For example, when using low energyBluetooth communication (BLE) as out-band communication, because datacan be transmitted at a transmission rate of up to 1-2 Mbps and anaverage of several hundred kbps, the authentication protocol can becompleted in a short time (e.g., tens to hundreds of ms).

FIG. 14 is a diagram for explaining an out-band communication connectionprocedure and an authentication procedure according to an embodiment.

Referring to FIG. 14 , the wireless power receiver 1010 may include anin-band communication module 1011 and an out-band communication module1012. The in-band communication module 1011 may perform messagemodulation, message transmission, message demodulation, etc. throughin-band communication, the out-band communication module 1012 mayperform message modulation, message transmission, message demodulation,and the like through out-band communication. The in-band communicationmodule 1011 and the out-band communication module 1012 may be physicallyseparated from each other, but they may be physically implemented by oneprocessor.

The wireless power transmitter 1020 may also include an in-bandcommunication module 1021 and an out-band communication module 1022. Thein-band communication module 1021 may perform message modulation,message transmission, message demodulation, etc. through in-bandcommunication, the out-band communication module 1022 may performmessage modulation, message transmission, message demodulation, and thelike through out-band communication. The in-band communication module1021 and the out-band communication module 1022 may be physicallyseparated from each other, they may be physically implemented by oneprocessor.

Hereinafter, for convenience of description, it is assumed that BLEcommunication is used as out-band communication.

The wireless power receiver 1010 transmits a BLE connection requestmessage through in-band communication (S1011).

TABLE 4 b7 b6 b5 b4 b3 b2 b1 B0 BLE device Address_B0 B1 BLE deviceAddress_B1 B2 BLE device Address_B2 B3 BLE device Address_B3 B4 BLEdevice Address_B4 B5 BLE device Address_B5

Referring to [Table 4], the BLE connection request message may include,for example, 6-byte, information on the Bluetooth device address of thewireless power receiver 1010 (Bluetooth Device Address).

The wireless power transmitter 1020 that has received the BLE connectionrequest message from the wireless power receiver 1010 transmits a BLEconnection response message in response to the BLE connection requestmessage (S1012).

The BLE connection request message may include, for example, 6-byte,Bluetooth device address of the wireless power transmitter 1020 (seeTable 4).

The wireless power receiver 1010 and the wireless power transmitter 1020may establish a BLE connection based on the received counterpart'sBluetooth device address (S1030).

Steps S1011, S1012 and S1030 may be performed in a negotiation (orrenegotiation) phase or a power transfer phase.

After the out-band communication (BLE) connection between the wirelesspower receiver 1010 and the wireless power transmitter 1020 isestablished, the authentication message according to the authenticationprotocol is transmitted/received through the out-band communication.

Referring to FIG. 14 , the wireless power receiver 1010 may transmitGET_DIGEST to the wireless power transmitter 1020 through out-bandcommunication to initiate an authentication protocol and request DIGESTfrom the wireless power transmitter 1020 (S1041).

The wireless power transmitter 1020 that has received the GET_DIGEST maytransmit the DIGEST to the wireless power receiver 1010 through out-bandcommunication (S1042).

The wireless power receiver 1010 receiving the DIGEST checks whether thedigest and the public key of the wireless power transmitter 1020 arecached in the memory, if digest and public key are not cached, thewireless power receiver 1010 may request a certificate by transmittingGET_CERTIFICATE to the wireless power transmitter 1020 through out-bandcommunication (S1043).

The wireless power transmitter 1020 that has received theGET_CERTIFICATE may transmit the CERTIFICATE to the wireless powerreceiver 1010 through out-band communication (S1044).

The wireless power receiver 1010 that has received the CERTIFICATE maytransmit CHALLENGE to the wireless power transmitter 1020 throughout-band communication (S1045).

The wireless power transmitter 1020 that has received the CHALLENGE maytransmit CHALLENGE_AUTH to the wireless power receiver 1010 throughout-band communication (S1046).

The wireless power receiver 1010 may finally check whether the wirelesspower transmitter 1020 is authenticated based on the receivedCHALLENGE_AUTH.

On the other hand, receiving the DIGEST in step S1042, the wirelesspower receiver 1010, which has confirmed that the digest and public keyof the wireless power transmitter 1020 are cached in the memory, skipssteps S1043 and S1044, CHALLENGE may be transmitted to the wirelesspower transmitter 1020 through out-band communication (S1045).

In FIG. 14 , the wireless power receiver 1010 transmits a BLE connectionrequest message, in response to this, the wireless power transmitter1020 shows an example of transmitting a BLE connection response message,although described based on this, according to an embodiment, thewireless power transmitter 1020 transmits a BLE connection requestmessage, in response to this, the wireless power receiver 1010 maytransmit a BLE connection response message.

In FIG. 14 , the wireless power receiver 1010 operates as anauthentication initiator, an example in which the wireless powertransmitter 1020 operates as an authentication responder is shown anddescribed based on this, according to an embodiment, the wireless powertransmitter 1020 operates as an authentication initiator, the wirelesspower receiver 1010 may operate as an authentication responder.

On the other hand, the wireless power receiver 1010 receives wirelesspower regardless of the progress of the authentication protocol (S1041to S1046) using out-band communication, a message for wireless powercontrol may be transmitted through in-band communication (S1051). Forexample, the wireless power receiver 1010 may transmit a control errorpacket (CE), a received power packet (RP), etc. in the power transferphase through in-band communication according to the transmission periodor timeout of each packet.

In addition, the wireless power transmitter 1020 also transmits wirelesspower regardless of the progress of the authentication protocol (S1041to S1046) using out-band communication, a response to the message forwireless power control received from the wireless power receiver 1010may be transmitted through in-band communication (S1052). For example,in the power transfer phase, the wireless power transmitter 1020 maytransmit responses such as ACK, NAK, ND, and ATN in response to thecontrol error packet CE and the received power packet RP through in-bandcommunication.

In addition, regardless of the progress of the authentication protocol(S1041 to S1046) using out-of-band communication, the wireless powertransmitter 1020 and the wireless power receiver 1010 maytransmit/receive a message for foreign object detection through in-bandcommunication.

According to the above-described embodiment, since authenticationmessages according to the authentication protocol are exchanged throughout-band communication, which has a faster communication speed thanin-band communication, the authentication protocol can proceed andcomplete quickly.

In addition, as a message for the control of wireless power, inparticular, a control error packet (CE) and a received power packet(RP), since messages that must be transmitted periodically due to arequired timeout are transmitted/received through in-band communication,a message for wireless power control can be stably transmitted/receivedregardless of the progress of the authentication protocol. Therefore, itis possible to control the wireless power stably, and to prevent theinterruption of wireless power transmission due to the elapse of atimeout of the message for controlling the wireless power.

In addition, since messages for foreign object detection aretransmitted/received through in-band communication, it is possible toperform foreign object detection regardless of the progress of theauthentication protocol. Accordingly, it is possible to immediatelydetect and respond to a foreign object existing between the wirelesspower transmitter 1020 and the wireless power receiver 1010.

FIG. 15 is a diagram for explaining an out-band communication connectionprocedure and an authentication procedure according to anotherembodiment.

Referring to FIG. 15 , compared with the embodiment described withreference to FIG. 14 , an outband communication connection procedure isdifferent. This embodiment will also be described on the premise thatBLE communication is used as out-band communication for convenience ofdescription.

The wireless power receiver 1010 transmits a data packet (hereinafter,referred to as a first packet) including information on its ownBluetooth device address through in-band communication (S1021). Thefirst packet may include, for example, 6-byte, Bluetooth device addressinformation of the wireless power receiver 1010 (see Table 4).

Then, in order to request information on the Bluetooth device address ofthe wireless power transmitter 1020, the wireless power receiver 1010may transmit a general request packet (GRQ/ble) through in-bandcommunication (S1022). The message field of the general request packet(GRQ/ble) transmitted in step S1022 may include a header value of apacket including information on a Bluetooth device address transmittedby the wireless power transmitter 1020.

The wireless power transmitter 1020 that has received the generalrequest packet (GRQ/ble) requesting a packet including information onthe Bluetooth device address from the wireless power receiver 1010transmits a data packet (hereinafter, a second packet) includinginformation on its own Bluetooth device address through in-bandcommunication (S1023). The second packet may include, for example,6-byte, Bluetooth device address information of the wireless powertransmitter 1020 (see Table 4).

The wireless power receiver 1010 and the wireless power transmitter 1020may establish a BLE connection based on the received counterpart'sBluetooth device address (S1030).

Since the descriptions of steps S1041 to S1046 and steps S1051 and S1052are substantially the same as in the above-described embodiment,additional description thereof will be omitted.

FIG. 16 is a diagram schematically illustrating a wireless powertransmission procedure according to an embodiment.

Referring to FIG. 16 , as described above, the wireless powertransmitter and the wireless power receiver may enter a power transferphase (Power Transfer) through a ping phase (Ping), a configurationphase (CONFIG), and a negotiation phase (NEGO).

In the ping phase, configuration phase, and negotiation phase, thewireless power transmitter and the wireless power receivertransmit/receive messages required in each step through in-bandcommunication.

After that, in the negotiation phase or power transfer phase, asdescribed with reference to FIG. 14 or FIG. 15 , the wireless powertransmitter and the wireless power receiver exchange address informationfor each out-band communication connection (S1011-S1012 or S1021-S1023),they establish an out-band communication connection based on this(S1030), they perform authentication through out-band communication.

Referring to FIG. 16 , the wireless power transmitter and the wirelesspower receiver perform wireless power transmission/reception in alow-power mode (for example, 5 W or less) until authentication of thewireless power transmitter and/or the wireless power receiver succeeds,after authentication of the wireless power transmitter and/or thewireless power receiver is successful, wireless powertransmission/reception may be performed in a high power mode (e.g.,equal to or greater than 5 W).

Accordingly, since high power is not received from the uncertifiedwireless power transmitter, the wireless power receiver can beprotected. In addition, since high power is not transmitted to anuncertified wireless power receiver, the wireless power transmitter canbe protected.

The wireless power transmitter in the embodiment according to theabove-described FIGS. 12 to 16 corresponds to the wireless powertransmission apparatus or the wireless power transmitter or the powertransmission unit disclosed in FIGS. 1 to 11 . Accordingly, theoperation of the wireless power transmitter in this embodiment isimplemented by one or the same or more than two combinations of eachcomponent of the wireless power transmitter in FIGS. 1 to 11 . Forexample, reception/transmission of a message or data packet according toFIGS. 12 to 16 is included in the operation of the communication/controlunit 120, 710 or 790.

The wireless power receiving apparatus in the embodiment according tothe above-described FIGS. 12 to 16 corresponds to the wireless powerreceiving apparatus or the wireless power receiver or the powerreceiving unit disclosed in FIGS. 1 to 11 . Accordingly, the operationof the wireless power receiver in this embodiment is implemented by oneor the same or a combination of two or more of the respective componentsof the wireless power receiver in FIGS. 1 to 11 . For example,reception/transmission of a message or data packet according to FIGS. 12to 16 may be included in the operation of the communication/control unit220, 810, or 890.

Since all components or steps are not essential for the wireless powertransmission method and apparatus, or the reception apparatus and methodaccording to the embodiment of the present document described above, anapparatus and method for transmitting power wirelessly, or an apparatusand method for receiving power may be performed by including some or allof the above-described components or steps. In addition, theabove-described wireless power transmission apparatus and method, or theembodiment of the reception apparatus and method may be performed incombination with each other. In addition, each of the above-describedcomponents or steps is not necessarily performed in the order described,and it is also possible that the steps described later are performedbefore the steps described earlier.

The above description is merely illustrative of the technical idea ofthe present document, those of ordinary skill in the art to which thepresent document pertains will be able to make various modifications andvariations without departing from the essential characteristics of thepresent document. Accordingly, the embodiments of the present documentdescribed above may be implemented separately or in combination witheach other.

Accordingly, the embodiments disclosed in the present document are notintended to limit the technical spirit of the present document, but toexplain, and the scope of the technical spirit of the present documentis not limited by these embodiments. The protection scope of the presentdocument should be construed by the following claims, all technicalideas within the scope equivalent thereto should be construed as beingincluded in the scope of the present document.

1-10. (canceled)
 11. A wireless power receiver, which supports anin-band communication and an out-of-band communication and receives awireless power from a wireless power transmitter, comprising: a powerpickup configured to receive the wireless power from the wireless powertransmitter; and a controller configured to control the reception of thewireless power, wherein the wireless power receiver: transmits, to thewireless power transmitter, out-of-band address information of thewireless power receiver, establishes a connection of the out-of-bandcommunication with the wireless power transmitter after transmitting theout-of-band address information, and performs a first operation via thein-band communication and a second operation via the out-of-bandcommunication.
 12. The wireless power receiver of claim 11, wherein thewireless power receiver transmits the out-of-band address informationvia the in-band communication.
 13. The wireless power receiver of claim12, wherein, in a negotiation phase, the wireless power receivertransmits the out-of-band address information.
 14. The wireless powerreceiver of claim 11, wherein the first operation and the secondoperation are related to operations in a power transfer phase.
 15. Thewireless power receiver of claim 14, wherein the first operationincludes a transmission of a control error (CE) packet or a transmissionof a received power (RP) packet.
 16. The wireless power receiver ofclaim 14, wherein the second operation includes an authenticationprocedure.
 17. The wireless power receiver of claim 11, wherein theout-of-band communication is a bluetooth low energy (BLE) communication.18. A wireless power transmitter, which supports an in-bandcommunication and an out-of-band communication and transfer a wirelesspower to a wireless power receiver, comprising: a power converterconfigured to transfer the wireless power to the wireless powerreceiver; and a controller configured to control the transfer of thewireless power, wherein the wireless power transmitter: receives, fromthe wireless power receiver, out-of-band address information of thewireless power receiver, establishes a connection of the out-of-bandcommunication with the wireless power receiver after receiving theout-of-band address information, and performs a first operation via thein-band communication and a second operation via the out-of-bandcommunication.
 19. The wireless power transmitter of claim 18, whereinthe wireless power transmitter receives the out-of-band addressinformation via the in-band communication.
 20. The wireless powertransmitter of claim 19, wherein, in a negotiation phase, the wirelesspower transmitter receives the out-of-band address information.
 21. Thewireless power transmitter of claim 18, wherein the first operation andthe second operation are related to operations in a power transferphase.
 22. The wireless power transmitter of claim 21, wherein the firstoperation includes a reception of a control error (CE) packet or areception of a received power (RP) packet.
 23. The wireless powertransmitter of claim 21, wherein the second operation includes anauthentication procedure.
 24. The wireless power transmitter of claim18, wherein the out-of-band communication is a bluetooth low energy(BLE) communication.